In the present study, a choice procedure was used in an outpatient methadone maintenance clinic to examine preferences for different double-blind methadone dose increases in 5 male patients. Subjects chose between 50 mg vs. 50 mg, 60 mg, 75 mg and 100 mg of methadone. In the 50 mg vs. 50 mg condition, each alternative was selected equally often. Percent selection of the higher doses (60, 75 and 100 mg) over the 50 mg dose of methadone increased in a dose-related fashion. Subject self-reports were consistent with methadone's opiate-like properties with dose-related trends being noted in most scales (e.g. opiate effects, drug liking). Overall, the results show that a choice procedure can be used successfully to assess the reinforcing properties of drugs in methadone maintenance patients and that methadone dose increases can function as a reinforcer in this population even under blind dosing conditions.