Determining the extent of alcohol and other drug use among Latino youth is hampered by several limitations in existing data. The fragmented picture of Latino adolescent substance abuse is particularly complicated by definitional and measurement problems. Substance use prevalence and patterns among Mexican Americans and Puerto Ricans are examined, especially with regard to alcohol, cocaine, heroin, and marijuana. Correlates of drug use among Latino adolescents are noted, including environmental, family, interpersonal, gender, and cultural factors. Due to the many risk factors faced by Latin youth, the importance of drug prevention and treatment programs is stressed. Abstracts of publications dealing with substance abuse among Latino youth are included. 140 references