We reviewed the incidence of malignant tumors among 923 patients with chronic renal failure, treated with hemodialysis (HD) in seven dialysis centers in Serbia between January 1983 and July 1993. Neoplasms were diagnosed in 45 cases (4.9%). The mean age of the cancer patients was 58.7 years. Eighteen cases (40.0%) were diagnosed in the first year after starting HD treatment and 21 (46.7%) cases were detected less than 5 years after induction of HD treatment. Most of the cancer patients (60.0%), especially the patients with Balkan endemic nephropathy (31.1 %), developed cancer of the urinary tract. We concluded that HD patients have a several times greater risk of developing malignant tumors than the general population.