**EXHIBIT 31.1**

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**RULE13a-14(a)/15d-14(a) CERTIFICATION OF CEO**

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I,Henry J. Theisen, certify that:

 

1.  I have reviewed this report on Form 10-Kof Bemis Company, Inc.;

 

2.  Based on my knowledge, this report does notcontain any untrue statement of a material fact or omit to state a materialfact necessary to make the statements made, in light of the circumstances underwhich such statements were made, not misleading with respect to the periodcovered by this report;

 

3. Based on my knowledge, the financial statements,and other financial information included in this report, fairly present in allmaterial respects the financial condition, results of operations and cash flowsof the registrant as of, and for, the periods presented in this report;

 

4. The registrant’s other certifyingofficer(s) and I are responsible for establishing and maintainingdisclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and15d-15(e)) and internal control over financial reporting (as defined inExchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant andhave:

 

a)Designed such disclosure controls and procedures, or caused such disclosurecontrols and procedures to be designed under our supervision, to ensure thatmaterial information relating to the registrant, including its consolidatedsubsidiaries, is made known to us by others within those entities, particularlyduring the period in which this report is being prepared;

 

b)Designed such internal control over financial reporting, or caused such internalcontrol over financial reporting to be designed under our supervision, toprovide reasonable assurance regarding the reliability of financial reportingand the preparation of financial statements for external purposes in accordancewith generally accepted accounting principles;

 

c)Evaluated the effectiveness of the registrant’s disclosure controls andprocedures and presented in this report our conclusions about the effectivenessof the disclosure controls and procedures, as of the end of the period coveredby this report based on such evaluation; and

 

d)Disclosed in this report any change in the registrant’s internal control overfinancial reporting that occurred during the registrant’s most recent fiscalquarter (the registrant’s fourth fiscal quarter in the case of an annualreport) that has materially affected, or is reasonably likely to materiallyaffect, the registrant’s internal control over financial reporting; and

 

5.  The registrant’s other certifying officer(s) andI have disclosed, based on our most recent evaluation of internal control overfinancial reporting, to the registrant’s auditors and the audit committee ofthe registrant’s board of directors (or persons performing the equivalentfunctions):

 

a)All significant deficiencies and material weaknesses in the design or operationof internal control over financial reporting which are reasonably likely toadversely affect the registrant’s ability to record, process, summarize andreport financial information; and

 

b)Any fraud, whether or not material, that involves management or other employeeswho have a significant role in the registrant’s internal control over financialreporting.

 
| Date   | February 27, 2009                                 |   | By  /s/ Henry J. Theisen |
|--------|--------------------------------------------------------|--------|--------------------------|
|   | Henry J. Theisen, President andChief Executive Officer |

 

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