FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * NUSSBAUM JOHN L   2. Issuer Name and Ticker or Trading Symbol PLEXUS CORP [PLXS] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner _____ Officer (give title below) __X__ Other (specify below) Chairman of the Board (Last) (First) (Middle) 55 JEWELERS PARK DRIVE 3. Date of Earliest Transaction (Month/Day/Year) 03/12/2010 (Street) NEENAH, WI 54956 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock, $.01 par value               4,199 I 401(k) (1) Common Stock, $.01 par value 03/12/2010   M   9,195 A $ 35.5469 126,413 D (2)   Common Stock, $.01 par value 03/12/2010   S   9,195 D $ 37.5 117,218 D (2)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Option to buy

$ 35.5469

03/12/2010

M

9,195

(3)

04/24/2010

Common Stock

9,195

$ 0

30,805

D

Option to buy

$ 22.04

(3)

12/01/2015

Common Stock

10,000

10,000

D

Option to buy

$ 23.855

(3)

12/01/2016

Common Stock

10,000

10,000

D

Option to buy

$ 27.465

(3)

11/23/2017

Common Stock

2,500

2,500

D

Option to buy

$ 22.17

(3)

01/28/2018

Common Stock

2,500

2,500

D

Option to buy

$ 24.21

(3)

04/28/2018

Common Stock

2,500

2,500

D

Option to buy

$ 29.71

(3)

07/29/2018

Common Stock

2,500

2,500

D

Option to buy

$ 14.17

(3)

11/19/2018

Common Stock

2,500

2,500

D

Option to buy

$ 14.625

(3)

02/02/2019

Common Stock

2,500

2,500

D

Option to buy

$ 20.953

05/04/2009(4)

05/04/2019

Common Stock

2,500

2,500

D

Option to buy

$ 25.751

08/03/2009(4)

08/03/2019

Common Stock

2,500

2,500

D

Option to buy

$ 33.999

01/25/2010(5)

01/25/2020

Common Stock

1,250

1,250

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
NUSSBAUM JOHN L 55 JEWELERS PARK DRIVE NEENAH, WI 54956	X			Chairman of the Board

Signatures

John L. Nussbaum, by Marilyn J. Bathke, Attorney-in-Fact		03/12/2010
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Shares of Plexus Corp. common stock held in the Plexus Corp. 401(k) Savings Plan as of the last date of a statement from the Plan's trustee.
(2)	Includes shares of Plexus Corp. common stock held in the John L. and Sandra K. Nussbaum Revocable Trust.
(3)	Options granted under the Plexus Corp. 2008 Long-Term Incentive Plan, or a predecessor plan, which qualifies under Rule 16b-3; now fully vested.
(4)	Options granted under the Plexus Corp. 2008 Long-Term Incentive Plan, which qualifies under Rule 16b-3; one half vested immediately, and the other half vest on the first anniversary of grant date.
(5)	Options granted under the Plexus Corp. 2008 Long-Term Incentive Plan, which qualifies under Rule 16b-3. Options immediately vested on grant date.
Remarks: Options were exercised and the resulting shares were sold pursuant to a Rule 10b5-1 plan.

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