Data were collected in eight counties between September 1990 and June 1991. A total of 1,869 arrests agreed to the interviews, and 1,365 of these consented to the full protocol, which included urinalysis. The self-report form used was identical to that used nationally. Results revealed that more than 36 percent of the arrestees had positive urinalysis results for any drug, including marijuana. Twenty-six percent had positive results for drugs other than marijuana. Cocaine was the most frequently used illicit drug and was used by 21 percent. Considerable variations existed among sites. Findings also indicated that alcohol abuse is still the main drug problem among arrestees. The analysis also focused on the relationship between drug use and arrest charge, the validity of self-reported drug use information of arrestees in smaller communities, the level of AIDS risk, and treatment history and perceived need for treatment. Figures, tables, and 16 references