The aim of this research was to estimate the mortality rates from drug-related deaths and other causes among problem drug users and population attributable risk of death due to opiate use in eight study sites in Europe. Opiate users were recruited from drug treatment centres during the period 1990-1998 and deaths followed up through national or local mortality registries. Gender-specific overall mortality rate, proportion of deaths by cause (drug-related, HIV, other), standardized mortality ratios (SMRs), and the attributable risk fraction (ARF) were estimated. Crude mortality rates varied from 1 per 100 person-years in the Dublin and London cohorts to 3.8 per 100 person-years in Barcelona. The highest drug-related mortality rate was 10 per 1000 person-years in Barcelona; the rates were ~7 per 1000 person-years in Denmark, London, Rome, and Vienna, and