Since the type of life-style often encountered in drug addicts is purported to influence their risk of cardiovascular disease, it seemed of interest to carry out a descriptive study on risk factors in young addicts. Twenty-four young intravenous drug addicts, mean age 29 years and mean body mass index (BMI) 22.5 (kg/m(-2)), were compared with 24 healthy people matched for age, gender and BMI. Both groups responded to a questionnaire on life-style risk factors. In addition, fasting blood samples were investigated for several coronary risk factors. Drug addicts had smoked more cigarettes (17 vs. 3 cigarettes/day) for a longer time period (15 vs. 5 years) than control subjects. They also had higher serum activities of liver enzymes related to alcohol abuse than controls. Level of physical activity and indicators of dietary intake of fruit, vegetables and salt were not significantly different between the groups. Blood lipid values, total cholesterol (5.1 vs. 5.6 mmol/l), and HDL-cholesterol (1.2 mmol/l), apolipoproteins, and an atherogenic index reflecting the balance between the atherogenic low density lipoproteins (LDL) and the antiatherogenic fraction (HDL), as well as the smoking-related factors fibrinogen and TBARS, were all similar in both groups. The study indicates that the prevalence of many known cardiovascular risk factors was similar in drug addicts and matched controls.