Data were obtained between April 1988 and January 1990. Arrestees were asked about perceived need for treatment, self-reported drug dependence, drug-related legal problems, attitudes toward professional care and treatment for drug use, and heroin use. Perceived need for treatment was positively related to the following predisposing factors: self-reported drug dependence, attitude toward treatment for drug use, and occurrence of drug-related problems other than dependence. Self-reported drug dependence was higher among women and accounted for the greater perceived need reported by women. Hispanics were less likely to perceive a need for treatment. Among daily drug users, both Hispanics and African Americans were less likely to indicate a need for treatment. These ethnic differences were not explained by self-reported drug dependence or any other predisposing factor. Implications of the findings for treatment referral, intake, and counseling are discussed. 34 references, 5 notes, and 6 tables (Author abstract modified)