Many researchers and practitioners cite concerns with maintenance and generalization as a serious issue for individuals with autism spectrum disorders (ASD), although few studies explicitly target performance of behaviors outside training environments. After an initial intervention failed to produce robust generalization outcomes, the present investigation examined the combinative effects of a peer-mediated intervention with video-based group instruction on the generalization of social skills by four high school students with ASD and co-occurring intellectual disability. A multiple probe across behaviors design was used to examine the effects of the packaged intervention on generalization of social skills to three natural settings within the high school. All participants demonstrated an increase in performance of social skills across all generalization environments following peer-mediated intervention for social skills that had been acquired--but minimally generalized--in a previous video-based group instruction study. Results suggest peer mediated intervention enhanced the generalization outcomes of an already effective intervention teaching social interaction to adolescents with ASD.