The effectiveness of a social skills training program for improving heterosocial interactions in persons with mental retardation was examined. Moderate to borderline mentally retarded subjects were selected based on problems with social anxiety and social skill deficits. Subjects were then randomly assigned to either a 12-session Dating Skills Program (DSP) or a wait list control (WLC) group. Assessments of social skills in a role-play test, knowledge about social/sexual situations, and social anxiety were obtained for all subjects at baseline, posttreatment, and at an 8-week follow-up. In addition, naturalistic observations were made of interactions of subjects in the DSP group. Subjects who participated in the DSP showed improvements in social skill and social/sexual knowledge at posttest and at follow-up compared to subjects in the WLC group. Social anxiety did not change over time for either group of subjects. Subjects who received the DSP increased interactions with persons of the opposite gender over time, while same-gender interactions decreased. The results replicate and extend previous research on the Dating Skills Program, and suggest that social skills training interventions may improve the heterosocial interactions of adults with mental retardation.