The Instrumental Enrichment program, designed to modify the cognitive structures of retarded, disadvantaged adolescents, was contrasted with a General Enrichment program both in a residential setting and a day center. This study is based on 57 matched pairs drawn from the total research sample of 218 adolescents. One group in a residential center (n = 24) and one group in a day center (n = 33) received Instrumental Enrichment; one group in a residential center (n = 24) and one group in a day center (n = 33) received General Enrichment. The Instrumental Enrichment program extended over 2 years, and the subjects were pre- and posttested on a battery of criterion measures: general and specific cognitive tests, scholastic achievement, classroom interaction, and self-concept. The results indicated significantly better performance by the groups receiving Instrumental Enrichment than by the groups receiving General Enrichment on the tests of specific cognitive functions and scholastic achievement and on some of the classroom interaction scales. Results for the residential groups compared with the day-center groups revealed significant differences on the tests of scholastic achievement, in favor of the residential groups and on the classroom interaction scales in favor of the day-center groups.