We developed and pilot-tested a comprehensive HIV prevention/sexual risk reduction intervention with 54 sexually abstinent girls and estimated the effect of the intervention on three antecedents of sexual risk behavior: information, motivation, and behavioral skills. Girls ages 14-18 were randomized into either (a) an AbsPlus intervention or (b) a structurally equivalent control group. Assessments were obtained at baseline and 3 months follow-up using audio computer assisted self-interview. The intervention resulted in a large effect for information (d = 1.11); small to large effects for the motivational measures (d = .34-.88), and a moderate effect for a measure of behavioral skills (d = .67). The results indicate that antecedents of sexual risk behavior change were improved by a gender-specific theoretically guided intervention.