The maintenance of premature mortality among opioid users is a highly significant public health issue. The main objective is to study the causes and age of mortality recorded in the population of opiate addicts (n = 1,998) treated at the Cangas Drug Addiction Assistance Unit (Pontevedra) over more than 30 years. The causes of mortality are classified into 4 groups: overdose, disease, suicide and trauma.The average age of mortality of the patients is compared with that of the general population residing in the same health area. Throughout the study, the premature mortality of these patients remained high, although with a tendency to decrease over time: up to 1998, the mean age of death was 31.8 years compared to 47.7 years since 1998.The mean age of death was always lower than that of the general population. Disease is the most prevalent cause of mortality (84% of the deceased) with a great difference compared to the other 3 groups. Despite the reduction in infections associated with parenteral use, there are still factors associated with an unhealthy lifestyle that, together with the aging of this population, explain to a large extent why the average age of death of these patients is not equal to that of the general population, which seems to force us to review the objectives of health and social intervention.