The relationship between mortality and nutritional status of 48 chronic dialysis patients (32 patients on haemodialysis (HD) and 16 on continuous ambulatory peritoneal dialysis (CAPD)) was studied over a 24-month period. Patients were scored individually according to relative body weight (RBW), S-transferrin, mid-arm muscle circumference (MAMC) and triceps skinfold thickness (TSF), and were given a total score from 0 (normal nutritional status) to 8 (severe protein-caloric malnutrition) at start of observation. The observation period was characterized by a significantly lower total nutritional score among surviving (n = 39) patients than among patients who died (n = 9) (Mann-Whitney, P less than 0.001). There was no difference in mortality between the two kinds of dialysis therapy (HD,CAPD). In conclusion, chronic dialysis patients with a poor nutritional status have a highly increased mortality. The presumably causal nature of this relationship makes prevention of protein-caloric malnutrition among dialysis patients a high priority task.