Ownership Submission
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 *
REDSTONE SUMNER M
  2. Issuer Name and Ticker or Trading Symbol
VIACOM INC [VIA, VIAB]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director __X__ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Chairman & CEO
(Last)
(First)
(Middle)
1515 BROADWAY
3. Date of Earliest Transaction (Month/Day/Year)
12/20/2005
(Street)

NEW YORK, NY 10036
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
Class B common stock 12/20/2005   M   200,000 A $ 20 620,805 D  
Class B common stock 12/20/2005   S(1)   1,200 D $ 33.2 619,605 D  
Class B common stock 12/20/2005   S(1)   2,900 D $ 33.21 616,705 D  
Class B common stock 12/20/2005   S(1)   2,300 D $ 33.23 614,405 D  
Class B common stock 12/20/2005   S(1)   3,600 D $ 33.24 610,805 D  
Class B common stock 12/20/2005   S(1)   800 D $ 33.25 610,005 D  
Class B common stock 12/20/2005   S(1)   2,900 D $ 33.26 607,105 D  
Class B common stock 12/20/2005   S(1)   1,000 D $ 33.27 606,105 D  
Class B common stock 12/20/2005   S(1)   2,200 D $ 33.28 603,905 D  
Class B common stock 12/20/2005   S(1)   800 D $ 33.29 603,105 D  
Class B common stock 12/20/2005   S(1)   2,085 D $ 33.3 601,020 D  
Class B common stock 12/20/2005   S(1)   1,000 D $ 33.31 600,020 D  
Class B common stock 12/20/2005   S(1)   1,100 D $ 33.32 598,920 D  
Class B common stock 12/20/2005   S(1)   1,000 D $ 33.33 597,920 D  
Class B common stock 12/20/2005   S(1)   3,600 D $ 33.34 594,320 D  
Class B common stock 12/20/2005   S(1)   900 D $ 33.36 593,420 D  
Class B common stock 12/20/2005   S(1)   3,800 D $ 33.37 589,620 D  
Class B common stock 12/20/2005   S(1)   3,900 D $ 33.38 585,720 D  
Class B common stock 12/20/2005   S(1)   3,200 D $ 33.39 582,520 D  
Class B common stock 12/20/2005   S(1)   2,400 D $ 33.4 580,120 D  
Class B common stock 12/20/2005   S(1)   8,300 D $ 33.41 571,820 D  
Class B common stock 12/20/2005   S(1)   6,800 D $ 33.42 565,020 D  
Class B common stock 12/20/2005   S(1)   9,300 D $ 33.43 555,720 D  
Class B common stock 12/20/2005   S(1)   13,100 D $ 33.44 542,620 D  
Class B common stock 12/20/2005   S(1)   12,300 D $ 33.45 530,320 D  
Class B common stock               265 I By 401(k)
Class B common stock               80,782,541 I By NAIRI, Inc. (2)
Class B common stock               200 I By Spouse

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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
Employee Stock Option (right to buy) (3) $ 20 12/20/2005   M     200,000   (4) 01/29/2006 Class B common stock 200,000 $ 0 0 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
REDSTONE SUMNER M
1515 BROADWAY
NEW YORK, NY 10036
  X   X   Chairman & CEO  

Signatures

 By: /s/ Michael D. Fricklas, Attorney-in-Fact   12/21/2005
**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) The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on November 3, 2005. Pursuant to the plan, the reporting person will exercise options that would otherwise expire on 1/29/06 and sell only that number of shares necessary so that the proceeds of the sales will be sufficient to pay the exercise price, income taxes and other fees associated with the exercise of these stock options.
(2) These securities are owned directly by NAIRI Inc., but may also be deemed to be beneficially owned by (1) NAIRI's parent corporation, National Amusements, Inc. (NAI), and (2) Sumner M. Redstone, who is the controlling stockholder of NAI.
(3) Right to buy under Issuer's long term incentive plan.
(4) Current.

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