In many countries opiate overdose remains the main source of the 10-fold excess mortality among opiate addicts, notwithstanding the effects of HIV/AIDS. 1 Treatment reduces mortality but can sometimes increase mortality transiently—for example, during the first few weeks of methadone maintenance treatment and among former opiate addicts after their release from prison. 2 3 The increase in mortality among released prisoners who were formerly opiate addicts has been attributed to loss of tolerance and erroneous judgment of dose when they returned to opiate use. 1 3 We wished to investigate whether opiate addicts who have undergone inpatient detoxification might have a similarly increased mortality after treatment. We followed up patients who received inpatient opiate detoxification, looked for evidence of increased mortality, and investigated the distinctive characteristics of patients who died.