Exhibit 3.2

AMERICAN RENAL ASSOCIATES HOLDINGS, INC.

(F/K/A C. P. ATLAS HOLDINGS, INC.)

BYLAWS

ADOPTED MARCH 18, 2010

ARTICLE I

MEETINGS OF STOCKHOLDERS

1.1 Place of Meeting and Notice. Meetings of the stockholders of the Corporation shall be held at such place either within or without the State of Delaware as the Board of Directors may determine.

1.2 Annual and Special Meetings. Annual meetings of stockholders shall be held, at a date, time and place fixed by the Board of Directors and stated in the notice of meeting, to elect a Board of Directors and to transact such other business as may properly come before the meeting. Special meetings of the stockholders may be called by the President for any purpose and shall be called by the President or Secretary if directed by the Board of Directors or requested in writing by the holders of not less than 25% of the capital stock of the Corporation. Each such stockholder request shall state the purpose of the proposed meeting.

1.3 Notice. Except as otherwise provided by law, at least 10 and not more than 60 clays before each meeting of stockholders, written notice of the time, date and place of the meeting, and, in the case of a special meeting, the purpose or purposes for which the meeting is called, shall be given to each stockholder.

1.4 Quorum. At any meeting of stockholders, the holders of record, present in person or by proxy, of a majority of the Corporation’s issued and outstanding capital stock shall constitute a quorum for the transaction of business, except as otherwise provided by law. In the absence of a quorum, any officer entitled to preside at or to act as secretary of the meeting shall have power to adjourn the meeting from time to time until a quorum is present.

1.5 Voting. Except as otherwise provided by law, all matters submitted to a meeting of stockholders shall be decided by vote of the holders of record, present in person or by proxy, of a majority of the Corporation’s issued and outstanding capital stock.

ARTICLE II

DIRECTORS

2.1 Number, Election and Removal of Directors. The number of Directors that shall constitute the Board of Directors shall not be less than one or more than fifteen. The first

Board of Directors shall consist of one Director. Thereafter, within the limits specified above, the number of Directors shall be determined by the Board of Directors or the stockholders. The Directors shall be elected by the stockholders at their annual meeting. Vacancies and newly created directorships resulting from any increase in the number of Directors may be filled by a majority of the Directors then in office, although less than a quorum, or by the sole remaining Director or by the stockholders. A Director may be removed with or without cause by the stockholders.

2.2 Meetings. Regular meetings of the Board of Directors shall be held at such times and places as may from time to time be fixed by the Board of Directors or as may be specified in a notice of meeting. Special meetings of the Board of Directors may be held at any time upon the call of the President and shall be called by the President or Secretary if directed by the Board of Directors. Telegraphic, facsimile or written notice of each special meeting of the Board of Directors shall be sent to each Director not less than two hours before such meeting. A meeting of the Board of Directors may be held without notice immediately after the annual meeting of the stockholders. Notice need not be given of regular meetings of the Board of Directors.

2.3 Quorum. One-third of the total number of Directors shall constitute a quorum for the transaction of business. If a quorum is not present at any meeting of the Board of Directors, the Directors present may adjourn the meeting from time to time, without notice other than announcement at the meeting, until such a quorum is present. Except as otherwise provided by law, the Certificate of Incorporation of the Corporation or these Bylaws, the act of a majority of the Directors present at any meeting at which there is a quorum shall be the act of the Board of Directors.

2.4 Committees. The Board of Directors may, by resolution adopted by a majority of the whole Board, designate one or more committees, including, without limitation, an Executive Committee, to have and exercise such power and authority as the Board of Directors shall specify. In the absence or disqualification of a member of a committee, the member or members thereof present at any meeting and not disqualified from voting, whether or not he or they constitute a quorum, may unanimously appoint another Director to act as the absent or disqualified member.

ARTICLE III

OFFICERS

3.1 Officers. The officers of the Corporation shall consist of a President and a Secretary, and such other additional officers with such titles as the Board of Directors shall determine, all of which shall be chosen by and shall serve at the pleasure of the Board of Directors. Such officers shall have the usual powers and shall perform all the usual duties incident to their respective offices. All officers shall be subject to the supervision and direction of the Board of Directors. The authority, duties or responsibilities of any officer of the Corporation may be suspended by the President with or without cause. Any officer elected or appointed by the Board of Directors may be removed by the Board of Directors with or without cause.

ARTICLE IV

INDEMNIFICATION

4.1 Indemnity Undertaking. To the fullest extent permitted by law (including, without limitation, Section 145 of the General Corporation Law of the State of Delaware (as amended from time to time, the “General Corporation Law”)), the Corporation shall indemnify any person who is or was made, or threatened to be made, a party to any threatened, pending or completed action, suit or proceeding (a “Proceeding”), whether civil, criminal, administrative or investigative, including, without limitation, an action by or in the right of the Corporation to procure a judgment in its favor, by reason of the fact that such person, or a person of whom such person is the legal representative, is or was a Director or officer of the Corporation, or is or was serving in any capacity at the request of the Corporation for any other corporation, partnership, joint venture, trust, employee benefit plan or other enterprise (an “Other Entity”), against judgments, fines, penalties, excise taxes, amounts paid in settlement and costs, charges and expenses (including attorneys’ fees and disbursements). Persons who are not Directors or officers of the Corporation may be similarly indemnified in respect of service to the Corporation or to an Other Entity at the request of the Corporation to the extent the Board of Directors at any time specifies that such persons are entitled to the benefits of this Article IV.

4.2 Advancement of Expenses. The Corporation shall, from time to time, reimburse or advance to any Director or officer or other person entitled to indemnification hereunder the funds necessary for payment of expenses, including attorneys’ fees and disbursements, incurred in connection with any Proceeding, in advance of the final disposition of such Proceeding; provided, however, that, if required by the General Corporation Law, such expenses incurred by or on behalf of any such Director, officer or other person may be paid in advance of die final disposition of a Proceeding only upon receipt by the Corporation of an undertaking, by or on behalf of such Director, officer or other person indemnified hereunder, to repay any such amount so advanced if it shall ultimately be determined by final judicial decision from which there is no further right of appeal that such Director, officer or other person is not entitled to be indemnified for such expenses.

4.3 Rights Not Exclusive. The rights to indemnification and reimbursement or advancement of expenses provided by, or granted pursuant to, this Article IV shall not be deemed exclusive of any other rights which a person seeking indemnification or reimbursement or advancement of expenses may have or to which such person hereafter may be entitled under any statute, the Certificate of Incorporation, these Bylaws, any agreement, any vote of stockholders or disinterested Directors or otherwise, both as to action in his or her official capacity and as to action in another capacity while holding such office.

4.4 Continuation of Benefits. The rights to indemnification and reimbursement or advancement of expenses provided by, or granted pursuant to, this Article IV shall continue as to a person who has ceased to be a Director or officer (or other person indemnified hereunder) and shall inure to the benefit of the executors, administrators, legatees and distributees of any such person.

4.5 Insurance. The Corporation shall have the power to purchase and maintain insurance on behalf of any person who is or was a Director, officer, employee or agent of the Corporation, or is or was serving at the request of the Corporation as a Director, officer, employee or agent of an Other Entity, against any liability asserted against such person and

incurred by such person in any such capacity, or arising out of such person’s status as such, whether or not the Corporation would have the power to indemnify such person against such liability under the provisions of this Article IV or the Certificate of Incorporation or under Section 145 of the General Corporation Law or any other provision of law.

4.6 Binding Effect. The provisions of this Article IV shall be a contract between the Corporation, on the one hand, and each Director and officer who serves in such capacity at any time while this Article IV is in effect and/or any other person indemnified hereunder, on the other hand, pursuant to which the Corporation and each such Director, officer or other person intend to be legally bound. No repeal or modification of this Article IV shall affect any rights or obligations with respect to any state of facts then or theretofore existing or thereafter arising or any proceeding theretofore or thereafter brought or threatened based in whole or in part upon any such state of facts.

4.7 Procedural Rights. The rights to indemnification and reimbursement or advancement of expenses provided by, or granted pursuant to, this Article IV shall be enforceable by any person entitled to such indemnification or reimbursement or advancement of expenses in any court of competent jurisdiction. The burden of proving that such indemnification or reimbursement or advancement of expenses is not appropriate shall be on the Corporation. Neither the failure of the Corporation (including its Board of Directors, its independent legal counsel and its stockholders) to have made a determination prior to the commencement of such action that such indemnification or reimbursement or advancement of expenses is proper in the circumstances nor an actual determination by the Corporation (including its Board of Directors, its independent legal counsel and its stockholders) that such person is not entitled to such indemnification or reimbursement or advancement of expenses shall constitute a defense to the action or create a presumption that such person is not so entitled. Such a person shall also be indemnified for any expenses incurred in connection with successfully establishing his or her right to such indemnification or reimbursement or advancement of expenses, in whole or in part, in any such proceeding.

4.8 Service Deemed at Corporation’s Request. Any Director or officer of the Corporation serving in any capacity (a) another corporation of which a majority of the shares entitled to vote in the election of its directors is held, directly or indirectly, by the Corporation or (b) any employee benefit plan of the Corporation or any corporation referred to in clause (a) shall be deemed, in each case, to be doing so at the request of the Corporation.

4.9 Election of Applicable Law. Any person entitled to be indemnified or to receive reimbursement or advancement of expenses as a matter of right pursuant to this Article IV may elect to have the right to indemnification or reimbursement or advancement of expenses interpreted on the basis of the applicable law in effect at the time of the occurrence of the event or events giving rise to the applicable Proceeding, to the extent permitted by law, or on the basis of the applicable law in effect at the time such indemnification or reimbursement or advancement of expenses is sought. Such election shall be made, by a notice in writing to the Corporation, at

the time indemnification or reimbursement or advancement of expenses is sought; provided, however, that if no such notice is given, the right to indemnification or reimbursement or advancement of expenses shall be determined by the law in effect at the time indemnification or reimbursement or advancement of expenses is sought.

ARTICLE V

GENERAL PROVISIONS

5.1 Notices. Whenever any statute, the Certificate of Incorporation or these Bylaws require notice to be given to any Director or stockholder, such notice may be given in writing by mail, addressed to such Director or stockholder at his address as it appears in the records of the Corporation, with postage thereon prepaid. Such notice shall be deemed to have been given when it is deposited in the United States mail. Notice to Directors may also be given by telegram.

5.2 Fiscal Year. The fiscal year of the Corporation shall be fixed by the Board of Directors.