The relationship of the child's socioeconomic status (SES) to improvement and generalization from cognitive-behavioral treatment was investigated by comparing high and low SES groups on teacher ratings, performance measures, and judges' ratings of improvement and maintenance of positive change. Fifty-eight teacher-referred classroom problem children (grades 2-6) who had served as treated subjects in one of three treatment outcome studies were examined. SES data were collected by administration of a questionnaire to the head of each household. The judges' ratings were performed on clusters of teacher ratings and clusters of performance measures that were present in each study. Results indicated that, despite SES group variation in level of performance, improvement, when it occurred, was evident for both high and low SES groups. In addition, there were significant differences on a number of the performance measures at pretreatment, posttreatment, and follow-up. Initial SES group differences in verbal ability as measured by the Peabody Picture Vocabulary Test (PPVT) appear to have been an important factor in these performance differences.