Recent information from epidemiological studies of alcohol and other drug use among gang members has documented that alcohol and other drug use is a serious problem among Latino gang members. Despite the extensive body of research on the onset of alcohol and other drug use among high-risk adolescents and the drug-using behaviors of gang members, particularly Latino gang members, there is a limited amount of research on the onset of alcohol and other drug-using behaviors among Latino gang members. The study described in this paper explores the patterns of alcohol and drug use initiation among male Latino gang members. Data presented in this report is from a preliminary analysis of 40 male gang members from a larger study of 81 male gang members. This preliminary analysis suggests important age and drug of choice differences between Latino gang members and other populations. Understanding the differences will assist in developing more effective programs to prevent the onset of alcohol and other drug use among Latino adolescent gang members.