Sixteen moderately and mildly retarded adults were selected from a group residential facility and randomly assigned to experimental and control groups. The experimental group received a 12-session interpersonal skills training program consisting of instruction in the following areas: (1) Introduction and Small Talk, (2) Asking for Help, (3) Differing with Others, and (4) Handling Criticism. The social skills instructional package included verbal instruction, modeling, role playing, feedback, contingent incentives, and homework. As a result of this training program, moderately and mildly retarded adults acquired new social skills as evidenced by performance on a situation role play assessment. These gains generalized to untrained role play situations but did not result in significant group differences when assessed in a more natural setting (i.e., local grocery store).