33 patients with chronic renal failure were divided into two groups. Group I consisted of 8 non-dialysed patients without any clinical or biochemical sign of liver disturbance nor any iron supplementation. Group II consisted of 25 maintenance hemodialysis (MHD) patients treated from 2 to 13 years. 19 subjects had chronic B hepatitis. Total exogenous iron load parenteral iron and/or blood transfusions) was calculated. Body iron overload (hemosiderosis) was assessed by liver iron concentration (LIC) in needle biopsy specimens according to Barry's method (less than 200 microgram/100 mg dry weight) and serum ferritin levels (less than 360 ng/ml). 4 patients whose serum ferritin was increased with or without hepatic fibrosis and with or without any organ dysfunction due to hemochromatosis received i.v. infusions of desferrioxamine in doses of 2 g at each dialysis. Serum ferritin levels were correlated with LIC (p less than 0.001) and iron load (p less than 0.001). Hemosiderosis was noted in 16 MHD patients (group II) and correlated with iron load. Hemochromatosis was noted in 4 patients (group II). 4 hemodialysed patients with iron overload were treated by desferrioxamine from 6 to 18 months. During this therapy, body iron stores fell and organ dysfunction (heart failure, hepatic cytolysis, anaemia, diabetes mellitus improved. Long-term chelation therapy by desferrioxamine was effective and the chelated iron was readily removed by dialysis. These data show the importance of precise evaluation of iron stores in MHD patients.