This study examined differences in intelligence between dropout delinquent adolescents and nondelinquent adolescents in Israel. It was part of research aimed at using psychological tests to characterize dropout delinquents. The participants, 215 adolescents at a psychoeducational center, were divided into three groups and were tested using the WISC-R: dropout delinquent adolescents living in residential institutions, dropout delinquent adolescents living at home, and nondelinquent adolescents living at home and enrolled in the formal education system. Results showed significant differences among the three groups in Verbal IQ, Performance IQ, Total IQ, and the Freedom from Distractibility factor, and pointed out the relative weakness of the dropout delinquent groups. (Contains 3 tables.) [This study was supported by the Education Research Committee at Beit Berl College, Israel, and the Schnitzer Foundation for Research of Israeli Economy and Society, Bar Ilan University, Israel.]