Addicts were maintained on a daily average methadone dose of 30 mg. Clients remaining in treatment for 6 and 12 months were compared to clients dropping out of treatment within the first 30 days and followed up 1 year later. Results showed that clients remaining in treatment showed signficant reductions in heroin usage and arrests, and large increases in full-time employment. One year later, the dropouts were doing as poorly as they had 1 year earlier. Methadone maintenance averaging 30 mg/day achieved similar "success' rates as other studies using larger daily doses, but did so at the expense of retaining fewer clients in treatment. It was recommended that treatment strategies be designed to impact at the first 30 days of treatment to retain them in treatment in view of the beneficial effects awaiting them if they stay.