Ownership Submission
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, 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 *
  Ross Paul
 2. Date of Event Requiring Statement (Month/Day/Year)
05/10/2005		 3. Issuer Name and Ticker or Trading Symbol
POWER ONE INC [PWER]
(Last)
(First)
(Middle)
740 CALLE PLANO		 4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
VP, Finance and CFO
 5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

CAMARILLO, CA 93012		 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 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)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
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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 of Derivative Security: 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
Employee Stock Option 1122-4/30/01 04/30/2002(1) 04/30/2011 Common Stock 1,000 $ 17.51 D  
Employee Stock Option 1649-10/1/01 10/01/2002(2) 10/01/2011 Common Stock 3,000 $ 5.77 D  
Employee Stock Option 2369-1/8/03 01/08/2004(3) 01/08/2013 Common Stock 10,000 $ 6.02 D  
Employee Stock Option 2767-7/21/04 02/23/2005(4) 07/21/2014 Common Stock 17,000 $ 9.12 D  
NQSO (Contingent Expiration) 10/01/2004(5) 10/01/2011 Common Stock 1,000 $ 5.77 D  

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
Ross Paul
740 CALLE PLANO
CAMARILLO, CA 93012		       VP, Finance and CFO  

Signatures

By: Randall H. Holliday, Attorney-in-Fact for 05/18/2005
**Signature of Reporting Person Date

Explanation of Responses:

* 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).
(1) For the noted grant, dated 4/30/01, 25% of the shares vest on each of the first, second, and third anniversaries of the date of grant, and 25% vest on 2/23/05, at which time all shares willl be fully vested and exercisable.
(2) For the noted grant, dated 10/1/01, 25% of the shares vest on each of the first, second, and third anniversaries of the date of grant, and 25% vest on 2/23/05, at which time all shares will be fully vested and exercisable.
(3) For the noted grant, dated 1/8/03, 25% of shares vest on the first anniversary of the date of grant, 25% on the second anniversary of the date of grant, and 50% on 2/23/05.
(4) All shares vest on 2/23/05.
(5) For the noted grant, the option expires on the earlier to occur of (a) six months plus one day following the Trigger Date (as defined in the grant agreement), or (b) tenth anniversary of the date of grant. The shortened period for exercise associated with alternative (a) may occur at any time once a Trigger Date has occurred, even if same occurs after vesting of the option.

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