The aim of the study was to evaluate the nutritional status of opiate dependent patients before and after 4 years of participation in the methadone maintenance treatment. The examinations were performed in 30 opiates addicted persons (7 women and 23 men). The initial examination (exam 1) was done during the patients qualification for the methadone program, preceding methadone administration and final examination (exam 2) after 4 years of the treatment. In order to estimate the nutritional status body mass, the height, the arm circumference and the thickness of the triceps and subscapular fat-skin folds were measured. On the basis of them the BMI and mid arm muscle circumference (MAMC) were counted. The measurements of the body composition (using the bioimpedance method) were performed. The changes between the results of subsequent examination were tested using the t-Student test. In the examination that took place after 4 years of follow-up, body weight loss in the group of women was observed (mean--1.7 kg). It was followed by the decrease of BMI value (from 20.3 to 19.8 kg/m2). In both examinations the percentage of fatty tissue in general body mass was significantly below recommended values (10.7% in both examinations--the recommended values are 20%-22%). In the group of men an increase in body weight (mean--8.8 kg) and BMI value (from 23.3 to 25.9 kg/m2) was noticed. Arm circumference, muscle arm circumference and fat-skin folds values were increased. The analysis of particular body components showed increased fatty body mass (11.9% in the first and 18.5% in the second examination--the recommended values 16-19%) together with the decrease of lean body mass and body water.