This study investigated whether behavior disordered children would decrease aggressive behavior if their social interest were developed. Three hypotheses that were tested predicted that there would be a significant difference between the control group and the experimental group on adjusted mean scores on aggressive behavior on post test scores. The measuring instruments used were the Child Behavior Checklist Parent Report Form, the Child Behavior Checklist Teacher Report Form, and the Child Behavior Checklist Director Observation Form. It was also predicted that there would be a significant difference between the control group and the experimental group on post test adjusted mean scores as measured on the Social Interest Scale. An analysis of covariance was employed to test the data. Behavior disordered students in the experimental group participated in three activities designed to develop their social interest. They participated in peer tutoring, socialization with nursing home residents, and group discussions. Data were collected from parents, teachers, and observers of behavior disordered students in an elementary school in Northwest Louisiana during the summer term of 1987. Teachers did report a statistically significant difference between the experimental and the control groups in the decrease of aggressive behavior. These results are in accord with predictions …