This study describes the development and validation of 4 videos designed to assess adolescent cognitive appraisals and understanding of social events (the CAUSE Videos). Story lines varied in outcome (2 negative and 2 ambiguous). Convergent and divergent validity were tested in samples of college freshmen and sophomores. As hypothesized, threatening interpretations during ambiguous situations were positively associated with trait hostility (convergent validity) but were not significantly associated with aggression (divergent validity). Negative video interpretations were not significantly associated with hostility or aggression. These videos provide a valid method for assessing adolescents' appraisals of ambiguous and negative social situations in a laboratory setting and may be used to test hypotheses about cognitive processes underlying associations such as that between low socioeconomic status and health in adolescents.