Comparatively few studies have examined the effects of methadone given during a clinical detoxification programme. Furthermore, their results are different especially because of changing drop-out rates. This study was carried out on a drug-detoxification ward and investigated the effects of methadone given to alleviate withdrawal symptoms. Comparisons were undertaken with patients withdrawn during a one-year period before methadone was available. No significant difference was found between drop-out rates of patients with methadone-supported detoxification (n = 113, drop-out rate: 41.6%) and patients who did not receive methadone during detoxification (n = 108, drop-out rate: 37.0%). Nevertheless the drop-out rate in the first three days of withdrawal was reduced from 15.7% to 8.0%. On average the critical drop-out moment shifted from 5.3 days to 10.1 days. Interpretations of these findings should take into account, that the number of patients who underwent a voluntary detoxification programme for the first time was nearly doubled after methadone was offered on the ward and, additionally, many more patients tried to withdraw from methadone taken within an outpatient methadone-maintenance programme.