Films have long been a major influence on youth, and their content changed dramatically with the demise of the production code in the 1960s. To understand changes in film content, the Coding of Health and Media Project (CHAMP) analyzed the top-30 grossing movies from 1950 to 2004. This chapter presents trends in gender and youth representation, as well as in portrayal of tobacco and alcohol use, and sex and violence. Bandura's social cognitive theory of mass communication is used to explain how such content may influence audiences. Over the study period, youth and male characters were increasingly represented. Consistent with a cultural shift in attitudes toward tobacco and alcohol, portrayal in both decreased. However, violence (especially as committed by youth) and sex increased. Although the MPAA rating system (G, PG, PG13, R) was intended to inform movie audiences of problematic content, the system restricted sexual content far better than violent content.