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Exhibit 12.1

# CERTIFICATION

I, Shaike Orbach, certify
that:

1.    
           I have reviewed this annual report on Form 20-F of Silicom Ltd.;

2.    
          Based on my knowledge, this annual 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 annual report;

3.    
          Based on my knowledge, the financial statements, and other financial information
          included in this annual report, fairly present in all material respects the
          financial condition, results of operations and cash flows of the Company as of,
          and for, the periods presented in this annual report;

4.    
          The Company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 15(d)-15(f)) for the
          Company 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 Company, including its
consolidated           subsidiary, is made known to us by others within those entities,
particularly           during the period in which this annual 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 Company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 Companys internal
control over           financial reporting that occurred during the period covered by the
annual report           that has materially affected, or is reasonably likely to
materially affect, the           Companys internal control over financial
reporting; and
| | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



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5.    
          The Companys other certifying officer and I have disclosed, based on our
          most recent evaluation of internal control over financial reporting, to the
          Companys auditors and the audit committee of Companys board of
          directors:

| | (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 Company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 Companys internal control
over           financial reporting.
| | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | Date:
March 22, 2009
| | --------------------

| |  | /S/ Shaike Orbach
Shaike Orbach, Chief Executive Officer
| |  | ----------------------------------------------------------------------

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