CERTIFICATIONS PURSUANT TO SECTION 302
EX-99.CERT

                                 CERTIFICATIONS

I, R. Jay Gerken, certify that:

1.   I have reviewed this report on Form N-CSR of Smith Barney Investment Series
     - Smith Barney International Fund;

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, changes in net
     assets, and cash flows (if the financial statements are required to include
     a statement of cash flows) of the registrant as of, and for, the periods
     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 Rule 30a-3(c) under the Investment Company Act of 1940) 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)  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 a date
         within 90 days prior to the filing date of this report based on such
         evaluation; and

     c)  Disclosed in this report any change in the registrant's internal
         control over financial reporting that occurred during the registrant's
         most recent fiscal half-year (the registrant's second fiscal half-year
         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 officers and I have disclosed 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 data; 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:  January 5, 2004                           /s/ R. Jay Gerken
                                               ---------------------------------
                                                   R. Jay Gerken
                                                   Chief Executive Officer



I, Richard L. Peteka, certify that:

1.   I have reviewed this report on Form N-CSR of Smith Barney Investment Series
     - Smith Barney International Fund;

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 information included in this report,
     and the financial statements on which the financial information is based,
     fairly present in all material respects the financial condition, results of
     operations, changes in net assets, and cash flows (if the financial
     statements are required to include a statement of cash flows) of the
     registrant as of, and for, the periods 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 rule 30a-3(c) under the Investment Company Act) 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)  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 a date
         within 90 days prior to the filing date of this report based on such
         evaluation; and

     c)  Disclosed in this report any change in the registrant's internal
         control over financial reporting that occurred during the registrant's
         most recent fiscal half-year (the registrant's second fiscal half-year
         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 officers and I have disclosed 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 data; 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:  January 5, 2004                        /s/ Richard L. Peteka
                                              -------------------------------
                                                Richard L. Peteka
                                                Chief Financial Officer