DVR-based targeted advertising is described. In an embodiment, a targeted advertisement system includes a DVR, an advertisement data store, and an advertisement manager. The DVR records media content, maintains the recorded media content for on-demand viewing, and provides the recorded media content for viewing when requested. The advertisement manager designates advertisement region(s) in the recorded media content as the media content is being recorded, where an advertisement region includes a first boundary and a second boundary to designate the advertisement region in the media content. The advertisement manager monitors a first data stream of the recorded media content when it is rendered for viewing to detect that a playback position of the first data stream has crossed an advertisement region boundary, and to initiate that an advertisement obtained from the advertisement data store be provided as a second data stream to render the advertisement for viewing.