A 2-year study was done on the effect of group therapy on the teacher-perceived classroom behavior of 82 hyperactive minority boys (ages 10-16 years) in a day school for disruptive children. By the end of the study, there were a minimum of four behaviors which indicated that the group therapy was accomplishing a statistically significant change in the experimental group: at the .05 level of significance, the experimental group was less likely to require assistance from others and to require teacher intervention for misbehavior than were the controls; and at the .62 level of significance they were less likely to flare up at classmates and to hit or push others. Among other findings was that the experimental group, overall, were more controlled in the classroom and less likely to interrupt classroom routine than were those not receiving group therapy. (A bibliography, a copy of the teacher rating form, and tabular data are appended). (DLS)