To establish the extent of health services, including inpatient, emergency room, and outpatient care utilized by illicit drug users during the previous year, we surveyed 77 drug abusers, who were not known to be HIV-positive, entering a detoxification unit and a comparison group of 70 drug nonusers. Over the previous year, drug abusers had a greater number of visits to their usual source of care, to emergency rooms, and to other sites than drug nonusers. Drug abusers were significantly more likely to have been hospitalized during the past year. Using a logistic model including sociodemographic factors, drug abusers were 2.3 times as likely to use an emergency room and 6.7 times as likely to be hospitalized as drug nonusers. We conclude that drug abusers are heavy users of health services compared to a group of drug nonusers.