There has been much speculation about the nature and extent of mortality among drug injectors in Glasgow. In order to determine injectors' mortality rate and compare this rate to the general population, identifier information from 459 drug injectors who received treatment for drug misuse in Glasgow between 1982 and 1994 was linked to the Scottish Mortality Register. The average duration of follow-up from cohort entry was 5.5 years and 10.2 years from commencement of drug injection. By the end of 1994, 53 cohort members had died. The average annual mortality rate of 1.8% was the same as that observed in a London cohort followed-up from 1969 to 1991. However, the excess mortality ratio (EMR) of 22.0 was almost double the London rate (11.9) because of the much lower average age of mortality (26.3 vs. 38.2 years). There was no significant time trend in EMR. Kaplan-Meier hazard analyzes show that younger patients and those who were HIV positive had significantly elevated mortality rates. The main cause of death was overdose, although it is unclear how many were accidental and how many intentional. Three of the six fatalities among HIV positive injectors were AIDS related. This study enables the first realistic assessment of the hypothesis that drug-related deaths in Glasgow are especially high. In relation to other populations of drug injectors, the annual mortality rate is comparable, although the average age of mortality is much lower in Glasgow. Consequently, in comparison to the general population, the mortality rate of drug injectors is higher in Glasgow compared to other cities.