<PAGE>
                                                                    EXHIBIT 31.1

                                 CERTIFICATIONS

I, Richard F. Pops, certify that:

1.  I have reviewed this quarterly report on Form 10-Q of Alkermes, Inc.;

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 material
    respects the financial condition, results of operations and cash flows
    of the registrant as of, and for, the period presented in this report;

4.  The registrant's other certifying officers and I are responsible for
    establishing and maintaining disclosure controls and procedures (as
    defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) 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)  [Paragraph omitted in accordance with SEC transition instructions
        contained in SEC Release No. 34-47986];

    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 the end of the period covered by 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 registrant's most recent fiscal year 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 officers and I have disclosed, based
    on our most recent evaluation of internal controls over financial
    reporting, 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 controls 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 controls over financial reporting.


Date:  August 6, 2004

                                               /s/ Richard F. Pops
                                               ---------------------
                                               Richard F. Pops
                                               Chief Executive Officer