SEC Form 3

FORM 3

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

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1. Name and Address of Reporting Person* McGrath Marlene Mary (Last) (First) (Middle) 3M CENTER (Street) ST. PAUL MN 55144-1000 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 04/04/2012	3. Issuer Name and Ticker or Trading Symbol 3M CO [ MMM ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director 10% Owner X Officer (give title below) Other (specify below) Sr VP - Human Resources	5. If Amendment, Date of 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

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	1,949	D

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Restricted Stock Units	(2)	(2)	Common Stock	911	(1)	D
Non-qualified Stock Option (Right to Buy)	05/12/2005	05/09/2014	Common Stock	2,020	84.4	D
Non-qualified Stock Option (Right to Buy)	05/09/2007	05/09/2016	Common Stock	2,236	87.35	D
Non-qualified Stock Option (Right to Buy)	05/08/2008	05/08/2017	Common Stock	2,560	84.78	D
Non-qualified Stock Option (Right to Buy)	05/13/2009	05/13/2018	Common Stock	1,131	77.18	D
Non-qualified Stock Option (Right to Buy)	02/09/2010	02/08/2019	Common Stock	1,335	54.11	D
Non-qualified Stock Option (Right to Buy)(3)	02/09/2011	02/07/2020	Common Stock	4,100	78.72	D
Non-qualified Stock Option (Right to Buy)(4)	02/08/2012	02/08/2021	Common Stock	3,573	89.47	D
Non-qualified Stock Option (Right to Buy)(5)	02/07/2013	02/07/2022	Common Stock	5,360	87.89	D

Explanation of Responses:

1. Each restricted stock unit represents a contingent right to receive one share of 3M common stock.

2. The restricted stock units will vest on 2/9/2013.

3. This option becomes exercisable in equal installments on each of the first three anniversaries of the grant date (2/9/2010).

4. This option becomes exercisable in equal installments on each of the first three anniversaries of the grant date (2/8/2011).

5. This option becomes exercisable in equal installments on each of the first three anniversaries of the grant date (2/7/2012).

	/s/ George Ann Biros, attorney-in-fact for Marlene M. McGrath	04/11/2012
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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