This study was designed to replicate earlier research examining the relationship between drug culture knowledge and substance use. The study explored how drug knowledge relates to problems caused by substance abuse, including drunkenness and driving while intoxicated. It examined the extent of youths' knowledge of street names for drugs, current prices, effects of drugs, drug apparatus, and methods of ingestion. Factors contributing to the growth of drug knowledge, including school performance, peers' substance use, and the age substances were first used, were analyzed. The findings showed substantial rates of substance use among this sample. Knowledge of the drug culture was more accurate and extensive among older students and males who are more likely to use drugs. There was no correlation between drug knowledge and intelligence or the other kinds of knowledge acquired in school. Exposure to peers' substance use was related to a higher level of drug culture familiarity. Youths who used drugs at an earlier age had a more extensive knowledge of the drug culture. Finally, drug knowledge was related to the number of different substances used by the respondents and to consequences of alcohol and drug use. The authors suggest that testing for knowledge of drug culture could be one way to identify youth with potential substance abuse problems. 6 tables and 13 references