The current study evaluated an intervention program, designed by the authors and based on the theory of sexual scripts and social learning theory, to reduce empirically established risk and vulnerability factors of sexual aggression. A sample of 1,181 university students in Germany (762 female) were randomly assigned to an intervention and a no-intervention control group. The intervention group completed six modules addressing established antecedents of sexual aggression perpetration and victimization: risky sexual scripts, risky sexual behavior, low sexual self-esteem, low sexual assertiveness, acceptance of sexual coercion, and perceived realism of pornography. After baseline (T1), intervention effects were measured one week after the last module (T2), nine months later (T3), and another 12 months later (T4). The intervention group showed significantly less risky sexual scripts and higher sexual self-esteem at T2, T3, and T4. The intervention indirectly reduced risky sexual behavior at T3 and T4 via less risky sexual scripts at T2 and increased sexual assertiveness at T3 and T4 via higher sexual self-esteem at T2. No intervention effects were found on the acceptance of sexual coercion and pornography realism. The implications of the findings for reducing the prevalence of sexual aggression perpetration and victimization are discussed.