SECURITIES AND EXCHANGE COMMISSION
Washington, D.C 20549

Schedule 13G/A

Under the Securities Exchange Act of 1934
(Amendment No. 19)

DIAGNOSTIC PRODUCTS CORPORATION

(Name of Issuer)

COMMON STOCK, NO PAR VALUE

(Title of Class of Securities)

252450-10-1

(CUSIP Number)

December 31, 2003

(Date of Event which Requires Filing This Statement)

     Check the appropriate box to designate the rule pursuant to which this Schedule is filed.

o Rule 13d-1(b)

o Rule 13d-1(c)

x Rule 13d-1(d)

*The remainder of this cover page shall be filed out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

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SCHEDULE 13G

CUSIP No. 252450-10-1

1.	NAME OF REPORTING PERSON     MARILYN ZIERING
2.	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP.
	(a) o
	(b) o
3.	SEC USE ONLY
4.	CITIZENSHIP OR PLACE OF ORGANIZATION     U.S.A.
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5.	SOLE VOTING POWER: 4,775,114
		6.	SHARED VOTING POWER: -0-
		7.	SOLE DISPOSITIVE POWER: 4,775,114
		8.	SHARED DISPOSITIVE POWER: -0-
9.	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON     4,775,114
10.	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
	o
11.	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9.     16.5%
12.	TYPE OF REPORTING PERSON     IN

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Item 1(a)	Name of Issuer: Diagnostic Products Corporation
Item 1(b)	Address of Issuer’s Principal Executive Offices:
	5700 West 96th Street
	Los Angeles, California 90045
Item 2(a)	Name of Person Filing: Marilyn Ziering
Item 2(b)	Address of Principal Business Office:	5700 West 96th Street Los Angeles, CA 90045
Item 2(c)	Citizenship: U.S.A.
Item 2(d)	Title of Class of Securities: Common Stock
Item 2(e)	CUSIP Number: 252450-10-1
Item 3	Statement filed Pursuant to Rules 13d-1(b) or 13(d)-2(b) or (c):
	Not Applicable
Item 4(a)	Amount Beneficially Owned: 4,775,114 shares.
Item 4(b)	Percent of Class: 16.5%
Item 4(c)	For information regarding the number of shares as to which the reporting person has voting and dispositive power, see Items 5-8 of page 2.
Item 5	Ownership of 5% or Less of Class: Not Applicable
Item 6	Ownership of More than 5% on Behalf of Another Person: Not Applicable
Item 7	Identification and Classification of the Subsidiary which Acquired the Security Being Reported on by the Parent Holding Company: Not Applicable
Item 8	Identification and Classification of Members of the Group: Not applicable.
Item 9	Notice of Dissolution of Group: Not Applicable
Item 10	Certification: Not Applicable

     After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Dated: February 2, 2004	/S/ Marilyn Ziering
	Marilyn Ziering

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