Through a questionnaire administered to the youths, information was obtained on basic socio-demographic characteristics and involvement with drugs. A more detailed analyses of a subset of these data focused on types of drug involvements and attitudes toward certain illegal behaviors. Comparisons with data from other studies of runaways and of youth in school indicated that drug use and abuse was two-thirds times more prevalent for runaways than with the school youths. For school youths, alcohol, particularly beer, was the drug of choice, with everything else, except cigarettes, rated a magnitude lower; whereas, for runaways, the level of alcohol and cigarette use was rated very high together with illicit drug use. Factor analysis of drug behaviors revealed that for runaways and school youths, drug involvement converged around three categories of drugs: hard core illicit, drugs, licit conventional drugs and smokeless tobacco, but with different degrees of involvement. Runaways' attitudes toward illicit acts were more tolerant than those of school youths. In addition to drug abuse, intervention programs for runaway/homeless youth need to consider the complexity of psychosocial problems of this high risk group. 4 tables and 18 references (Author abstract modified)