**Exhibit 31.1**

**Certification by Chief Executive        Officer Pursuant to        Section 302 of the Sarbanes-Oxley Act of 2002**

        I, Dr. Eric A. Rose, M.D., certify that:

        1.     I have reviewed this annual report on Form 10-K of        SIGA Technologies, 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 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 Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over        financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f))        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 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 quarter (the registrant’s fourth fiscal quarter        in the case of an annual 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, based on our most recent evaluation of internal control 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 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: March 13, 2008
| /s/ Eric A. Rose        |   |
|-------------------------|--------|
| Dr. Eric A. Rose, M.D.  |   |
| Chief Executive Officer |   |

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