Development and initial validation are described for an instrument to assess the behavioral coping skills of adolescents. The Assessment of Behavioral Coping Skills (ABCS) was designed for use in the South Carolina Coping Skills Project, a school-based coping skills prevention program for adolescents at high risk for substance abuse. The ABCS consists of five videotaped vignettes or skits depicting adolescents in problematic situations (e.g., peer pressure to smoke marijuana, anxiety before an upcoming event, trying to make a date, an argument with parents). Questions follow each presentation, and respondents write their answers on a response form. Responses are coded for content and effectiveness of the coping responses using a scheme derived from the responses of 47 high-risk high school students for whom interrater reliability exceeded 80%. The ABCS was tested with 466 high-risk junior high and high school students, with a follow-up for 273 of these students conducted after 1 year. A sample of 77 adolescents from church youth groups, not considered at high risk, also completed the ABCS. Correlations indicated that the forms of the measure were comparable and that the measure was sensitive enough to detect changes brought about by preventive interventions. Although these preliminary findings support the stability, sensitivity, and discriminability of the developed measure, additional work is necessary to establish the construct validity of the measure. Four tables summarize the data. (SLD)