Methadone detoxification procedures are widely accepted as a satisfactory way of withdrawing opiate addicts from drugs. There have, however, been comparatively few empirical studies which have examined the development and course of withdrawal symptoms in opiate addicts in response to such detoxification procedures. This study investigates the opiate withdrawal syndrome in a group of 116 opiate addicts during and subsequent to a gradual oral methadone detoxification programme. Withdrawal symptoms peak at the end of the methadone schedule and decline steadily thereafter. Not until 40 days after the beginning of the withdrawal regime have symptom levels returned to normal. It is suggested that this protracted withdrawal response is not entirely satisfactory and alternative clinical and research options are proposed. The results fail to support the accepted view that dose is a major determinant of withdrawal severity. Low dose users did not experience less severe withdrawal symptoms than high dose users. This finding together with those of a previous study suggest that this issue also warrants further research attention.