This study determined whether the evoked potentials of N100 and P300 could distinguish among groups of delinquent (antisocial) drug users, delinquent non-drug users, and non- delinquent/non-drug users. From a sample of 35 adolescents, 17 were chosen who represented extremes of self-reported drug use and delinquent behavior. Three comparison groups were identified: Group 1 (7), high drug use/high delinquency; Group 2 (4), no drug use/high delinquency; and Group 3 (6), no drug use/no delinquency. The three groups were similar in age, IQ, race, and neighborhood characteristics. The subjects performed the auditory oddball task under conditions of low and high background noise. In the high background noise condition, Group 1 had longer latency P300 responses than Groups 2 and 3, and Group 2 had smaller N100 amplitude than Groups 1 and 3. Performance was similar for each group, and no group differences occurred in the low background noise condition. The results support and extend previous research on the relationship between attentional and cognitive processes, as well as delinquent and drug-using behaviors. 2 figures and 25 references