The gang members interviewed were recruited from neighborhoods believed to have high concentrations of gang members. The data were drawn from extensive fieldwork over the years 2001 and 2002. Descriptive data collected pertained to age of onset of alcohol and other drug use, types of drugs first used, the settings of first use, and the group association at the time of first use. The average age of onset of alcohol and other drug use was 11 years old, with 46 percent starting before this age. Sixty percent of the gang members reported they were with friends when they first started to use alcohol or other drugs, and 18 percent reported they were with family members. Thirty-eight percent of the gang members reported they were on the street when they first used alcohol or other drugs, which included alleys, parks, and street corners; 33 percent reported that they were in their parents' home, which was most often the mother's home. Forty-five percent of the gang members reported that they used alcohol first, followed by 33 percent who reported that they used marijuana first and 23 percent who reported starting with cigarettes. This preliminary analysis suggests significant age and drug-of-choice differences between Latino gang members and other populations. Recognition of these differences should assist in the design of alcohol and drug prevention programs for Latino adolescent gang members. 1 figure, 3 notes, and 30 references