Exhibit
31.1


CERTIFICATION
OF PRINCIPAL EXECUTIVE OFFICER


PURSUANT
TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002





I,
Elizabeth Plaza, certify that:





1.    I
have reviewed this quarterly report on Form 10-Q of Pharma-Bio Serv
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(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 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(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;
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:  June
15, 2009


/s/
      Elizabeth PlazaElizabeth
      PlazaPresident
      and Chief Executive Officer