Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for providing customized television advertisements. In one aspect, television advertising templates are used for generating customized television advertisements. The television advertisement templates include targeting criteria specifying targeting conditions for the television advertising template, which are conditions for selecting the television advertisement template for an advertisement availability, and content selection criteria specifying availability content associated with an advertisement availability for use in selecting variable advertisement content elements for inclusion in a customized television advertisement generated from the television advertising template. The variable advertisement content elements can include video elements, audio elements, and text elements.