Drug-related fatal poisonings were analysed in Hamburg from 1990 to 30th June 1999 with special attention to the role of methadone. The first methadone-related fatalities were observed in Hamburg three years after methadone maintenance treatment (MMT) was introduced in 1990. Meanwhile more than half of all fatal poisonings among drug addicts are monovalent or polydrug intoxications with evidence for methadone. From January 1997 until June 1999 methadone was the predominant cause of death in about 39% of all drug-related fatal poisonings while the proportion of mixed heroin/methadone intoxications was about 10%. The rising problem of methadone-related fatalities goes with a decline of monovalent heroin intoxications which decreased in the last 9 years from 60% to 11%. Sixty-five per cent of those who died of fatal methadone-related poisonings had no history of MMT (60% of those with methadone as predominant cause of death). Since take-home doses for up to 7 days are prescribed to the patient due to a change in the German Narcotics Act in 1998, the diversion of methadone into illegal markets may have been accelerated. This results in rising numbers of non-intentional methadone-related fatalities among addicts who have never been in MMT. The prerequisites for the prescription of take-home doses should be taken more serious. There is no doubt that MMT reduced the mortality rate among the great majority of patients in Hamburg but supreme efforts should be made to prevent or reduce fatal intoxications by methadone in the non-treatment group.