- Initial Statement of Beneficial Ownership (3)

FORM 3	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES	OMB APPROVAL OMB Number: 3235-0104 Expires: November 30, 2011 Estimated average burden hours per response... 0.5
	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

1. Name and Address of Reporting Person ^*

Trebing Richard

2. Date of Event Requiring Statement (MM/DD/YYYY) 12/23/2011

3. Issuer Name and Ticker or Trading Symbol

MENTOR GRAPHICS CORP [MENT]

(Last) (First) (Middle)

C/O MENTOR GRAPHICS CORPORATION, 8005 SW BOECKMAN ROAD

4. Relationship of Reporting Person(s) to Issuer (Check all applicable)

_____ Director _____ 10% Owner
___ X ___ Officer (give title below) _____ Other (specify below)
Principal Accounting Officer /

(Street)

WILSONVILLE, OR 97070

(City) (State) (Zip)

5. If Amendment, Date Original Filed (MM/DD/YYYY)

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	10451	D

*Table II - Derivative Securities Beneficially Owned ( e.g.* , puts, calls, warrants, options, convertible securities)**
1. Title of Derivate Security (Instr. 4)	2. Date Exercisable and Expiration Date (MM/DD/YYYY)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
1. Title of Derivate Security (Instr. 4)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	4. Conversion or Exercise Price of Derivative Security		6. Nature of Indirect Beneficial Ownership (Instr. 5)
Stock Option	9/25/2006	9/25/2012	Common Stock	6000	$5.66	D
Stock Option	11/4/2008	11/4/2014	Common Stock	2750	$11.74	D
Stock Option	9/26/2009	9/26/2015	Common Stock	2750	$8.41	D
Stock Option	⁽¹⁾	12/11/2018	Common Stock	3650	$5.17	D
Restricted Stock Units (RSUs)	⁽⁴⁾	⁽³⁾	Common Stock	1826	$0	D
Restricted Stock Units (RSUs)	⁽²⁾	⁽³⁾	Common Stock	5644	$0	D
Restricted Stock Units (RSUs)	⁽²⁾	⁽³⁾	Common Stock	3864	$0	D

Explanation of Responses:
( 1)	Option becomes exercisable over a four year period where on December 11, 2009 25% of the total shares granted vest and an additional 1/48th vest on each month thereafter.
( 2)	RSU vests annually over four years where 25% of the total shares vest on each of the first four anniversaries of the grant date.
( 3)	No expiration date applies.
( 4)	RSU was issued in the Stock Option Exchange. For vested options exchanged,the RSU vests annually after the first year with 50% of the total shares vesting each of the first two anniversaries. For unvested options exchanged, the RSU vests annually after the first year with 1/3 of the total shares vesting each of the first three anniversaries.

Reporting Owners
Reporting Owner Name / Address	Relationships
Reporting Owner Name / Address	Director	10% Owner	Officer	Other
Trebing Richard C/O MENTOR GRAPHICS CORPORATION 8005 SW BOECKMAN ROAD WILSONVILLE, OR 97070			Principal Accounting Officer

Signatures
Dean Freed, Attorney-in-fact for Richard Trebing		12/28/2011
^** 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.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.