At the Drug Detoxification, Rehabilitation, and Aftercare Program of the Haight-Ashbury Free Clinics, we conducted a double-blind, controlled, randomized clinical trial of imipramine in the treatment of cocaine and methamphetamine abusers. The purpose of the trial was to test the efficacy of imipramine as a treatment for stimulant dependence and to establish the feasibility of conducting a controlled clinical trial at the clinic under conditions that approximated usual clinical practice. Subjects were randomly assigned to receive either 10 or 150 mg/day of imipramine. Imipramine 10 mg/day was the control condition. Subjects could receive study medication for up to 180 days. One-hundred eighty-three subjects participated in the study: 151 were cocaine dependent and 32 were methamphetamine dependent. In addition to receiving study medication, all subjects were assigned to intensive drug abuse counseling, which included an HIV education component. Using an intention-to-treat analysis, we found that retention in treatment was significantly longer for subjects who were treated with 150 mg of imipramine compared to control. However, we found no consistent differences between the two groups of subjects in Beck Depression Inventory scores, stimulant craving, self-report of time since last use of stimulants, or percent of urinalyses positive for stimulants. The feasibility of conducting a controlled, randomized clinical trial of medication for treatment of drug abuse was established for this community clinic setting.