Longitudinal findings are presented on lifetime, past year, and magnitude of use of cigarettes, alcohol, and illicit drugs among non-Hispanic White (NHW), African-American, Cuban, Nicaraguan, Colombian, and Puerto Rican adolescent boys. The T-3 sample included 5,370 adolescents of whom 3,403 were Hispanic. About one-half the Hispanic sample was foreign born. Significant increases in lifetime use and magnitude of use of all three substances were found over the three data collection periods for all six groups. NHW and Hispanic adolescents had higher substance use rates than African-Americans. Most differences were not significant for NHW and Hispanic subgroups. Foreign-born Hispanics reported positive relationships between length of time in country and substance use. Significant relationships were found in two instances. Length of time in country was related to lifetime use of all substances for Cubans and for past year use of alcohol and illicit drugs. It was also significantly related to lifetime and past year use of alcohol and for lifetime illicit drug use among Nicaraguans. Although substance use did not vary greatly for different Hispanic groups, the authors suggest caution be used in offering generalizations, especially among young groups with diverse nativity and immigration histories.