This study evaluated the efficacy of a low-cost contingency management (CM) procedure in reducing concurrent cocaine and opioid use among methadone patients. Forty-two patients were randomly assigned to 12 weeks of standard treatment or standard treatment plus CM. CM patients eamed the opportunity to draw from a bowl and win prizes ranging from $1 to $ 100 in value for submitting samples negative for cocaine and opioids. Patients in the CM condition achieved longer durations of continuous abstinence than patients in the standard treatment condition, and these effects were maintained throughout a 6-month follow-up period. On average, patients in the CM condition earned $137 of prizes. These data suggest that this prize reinforcement procedure may be suitable for community-based settings.