EXHIBIT (A)(2)(1)

                         NATIXIS CASH MANAGEMENT TRUST
                           EXHIBIT TO SEC FORM N-CSR
                           SECTION 302 CERTIFICATION

I, John T. Hailer, certify that:

    1. I have reviewed this report on Form N-CSR of Natixis Cash Management
       Trust;

    2. Based on my knowledge, this report does not contain any untrue statement
       of a material fact or omit to state a material fact necessary to make
       the statements made, in light of the circumstances under which such
       statements were made, not misleading with respect to the period covered
       by this report;

    3. Based on my knowledge, the financial statements, and other financial
       information included in this report, fairly present in all materials
       respects the financial condition, results of operations, changes in net
       assets, and cash flows (if the financial statements are required to
       include a statement of cash flows) of the registrant as of, and for, the
       periods presented in this report;

    4. The registrant's other certifying officer and I are responsible for
       establishing and maintaining disclosure controls and procedures (as
       defined in Rule 30a-3(c) under the Investment Company Act of 1940) and
       internal control over financial reporting (as defined in Rule 30a-3(d)
       under the Investment Company Act of 1940) for the registrant and have:

       a. Designed such disclosure controls and procedures, or caused such
          disclosure controls and procedures to be designed under our
          supervision, to ensure that material information relating to the
          registrant, including its consolidated subsidiaries, is made known to
          us by others within those entities, particularly during the period in
          which this report is being prepared;

       b. Designed such internal control over financial reporting, or caused
          such internal control over financial reporting to be designed under
          our supervision, to provide reasonable assurance regarding the
          reliability of financial reporting and the preparation of financial
          statements for external purposes in accordance with generally
          accepted accounting principles;

       c. Evaluated the effectiveness of the registrant's disclosure controls
          and procedures and presented in this report our conclusions about the
          effectiveness of the disclosure controls and procedures, as of a date
          within 90 days prior to the filing date of this report based on such
          evaluation; and

       d. Disclosed in this report any change in the registrant's internal
          control over financial reporting that occurred during the second
          fiscal quarter of the period covered by this report that has
          materially affected, or is reasonably likely to materially affect,
          the registrant's internal control over financial reporting; and



    5. The registrant's other certifying officer and I have disclosed to the
       registrant's auditors and the audit committee of the registrant's board
       of directors (or persons performing the equivalent functions):

       a. All significant deficiencies and material weaknesses in the design or
          operation of internal control over financial reporting which are
          reasonably likely to adversely affect the registrant's ability to
          record, process, summarize, and report financial information; and

       b. Any fraud, whether or not material, that involves management or other
          employees who have a significant role in the registrant's internal
          control over financial reporting.

Date: February 21, 2008


                                                  /s/ John T. Hailer
                                                  ------------------------------
                                                  John T. Hailer
                                                  President and Chief Executive
                                                  Officer



                                                              EXHIBIT (A)(2)(2)

                         NATIXIS CASH MANAGEMENT TRUST
                           EXHIBIT TO SEC FORM N-CSR
                           SECTION 302 CERTIFICATION

I, Michael C. Kardok, certify that:

    1. I have reviewed this report on Form N-CSR of Natixis Cash Management
       Trust;

    2. Based on my knowledge, this report does not contain any untrue statement
       of a material fact or omit to state a material fact necessary to make
       the statements made, in light of the circumstances under which such
       statements were made, not misleading with respect to the period covered
       by this report;

    3. Based on my knowledge, the financial statements, and other financial
       information included in this report, fairly present in all materials
       respects the financial condition, results of operations, changes in net
       assets, and cash flows (if the financial statements are required to
       include a statement of cash flows) of the registrant as of, and for, the
       periods presented in this report;

    4. The registrant's other certifying officer and I are responsible for
       establishing and maintaining disclosure controls and procedures (as
       defined in Rule 30a-3(c) under the Investment Company Act of 1940) and
       internal control over financial reporting (as defined in Rule 30a-3(d)
       under the Investment Company Act of 1940) for the registrant and have:

       c. Designed such disclosure controls and procedures, or caused such
          disclosure controls and procedures to be designed under our
          supervision, to ensure that material information relating to the
          registrant, including its consolidated subsidiaries, is made known to
          us by others within those entities, particularly during the period in
          which this report is being prepared;

       d. Designed such internal control over financial reporting, or caused
          such internal control over financial reporting to be designed under
          our supervision, to provide reasonable assurance regarding the
          reliability of financial reporting and the preparation of financial
          statements for external purposes in accordance with generally
          accepted accounting principles;

       e. Evaluated the effectiveness of the registrant's disclosure controls
          and procedures and presented in this report our conclusions about the
          effectiveness of the disclosure controls and procedures, as of a date
          within 90 days prior to the filing date of this report based on such
          evaluation; and

       f. Disclosed in this report any change in the registrant's internal
          control over financial reporting that occurred during the second
          fiscal quarter of the period covered by this report that has
          materially affected, or is reasonably likely to materially affect,
          the registrant's internal control over financial reporting; and



    5. The registrant's other certifying officer and I have disclosed to the
       registrant's auditors and the audit committee of the registrant's board
       of directors (or persons performing the equivalent functions):

       g. All significant deficiencies and material weaknesses in the design or
          operation of internal control over financial reporting which are
          reasonably likely to adversely affect the registrant's ability to
          record, process, summarize, and report financial information; and

       h. Any fraud, whether or not material, that involves management or other
          employees who have a significant role in the registrant's internal
          control over financial reporting.

Date: February 21, 2008


                                                  /s/ Michael C. Kardok
                                                  ------------------------------
                                                  Michael C. Kardok
                                                  Treasurer