The media conglomerate controlled by billionaire Sumner Redstone earned $277 million, or 46 cents per share, compared with $407 million, or 65 cents per share, in the same quarter last year.
Excluding 3 cents per share in severance charges, adjusted earnings were 49 cents in the latest quarter.
Revenue slipped 14 percent to $3.3 billion.
Analysts projected income of 48 cents per share on sales of $3.5 billion.
New York-based Viacom Inc. owns a wide range of media properties including Paramount Pictures and the "Rock Band" video-game franchise.