Although group counseling procedures have been researched extensively for institutionalized offender populations, literature concerning group counseling with non-institutionalized offenders has been less evident. In addition, much confusion exists in the literature with regard to frustration tolerance, and the acquisition and modification of aggressive behavior. For the purposes of this research, frustration tolerance as outlined by Saul Rosenzweig and the theoretical base of social learning in the acquisition of aggressive behavior, were utilized . In sum, this study was designed to investigate three treatment methods and their effects on frustration tolerance and aggression for a population of non-institutionalized offenders. Thirty-nine clients under the supervision of the United States District Court for the District of Columbia were randomly assigned to one of three treatment groups. The treatment exposures consisted of: a) psychodrama and group counseling; b) films , audio-visual and group discussion; and c) normal probation and/or parole supervision as outlined by the Courts. The Rosenzweig Picture-Frustration Study and the Berea College Form Board were used as pre-test and as post-test measures for subjects in all three treatment groups. A Behavioral Rating Scale was developed to be used with the Berea College Form Board which consisted of 21 identifiable and/or definable physical and verbal behaviors. Computation of two Pearson product-moment correlation coefficients resulted in .71 for the pre-test and .83 for the post-test when comparisons were made between judges ratings on the Behavioral Ra ting Scale of subject's aggressive behaviors. Analysis of covariance with pre-test scores used as covariates was used in the analysis of the data. Results of the analysis were as follows: (1) There were no significant differences in mean scores between the three treatment groups in the acquisition of appropriate behaviors as measured on the (E), (I), (M) and (GCR) dimensions of the Rosenzweig Picture- Frustration Study. (2) There were no significant differences in mean scores between the three treatment groups in the acquisition of appropriate behaviors as measured on the Behavioral Rating Scale. While an analysis of the quantitative data does not support the use of psychodrama and group counseling, and the use of films and/ or audio-visual aids and group discussion as treatment methods to be used in the acquisition of appropriate behaviors, examination of the qualitative progress reports lend support to its continued use as treatment methods with offender populations. Meaningful relationships with probation officers and other group members were established, and in addition, "group members were able to look at themselves and discuss some of their problems." Further research, however, is recommended using similar techniques so that the effectiveness of this approach can be better evaluated.