EXHIBIT 31.1
 CERTIFICATION OF PRINCIPAL EXECUTIVE OFFICER
PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002
 I, Mihael H. Polymeropoulos, certify that:1.
    
    I have reviewed this annual report on Form 10-K of Vanda Pharmaceuticals Inc.;2.
    
    Based on my knowledge, this report does not contain any untrue statements 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 consolidated 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(s) 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
subsidiary, 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; andd.
    
    disclosed in this report any change in the registrants
internal control over financial reporting that occurred
during the registrants fourth fiscal quarter that has
materially affected, or is reasonably likely to materially
affect, the registrants internal control over financial
reporting.
 5.
    
    The registrants other certifying officer(s) 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;
andb.
    
    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 15, 2010
    /s/ Mihael H. PolymeropoulosMihael H. PolymeropoulosPresident and Chief Executive Officer
(Principal Executive Officer)