Endemic nephropathy (EN) is a renal disease of unknown etiology. In Croatia it occurs in the rural population in 14 villages located in the western part of Brodsko-Posavska county. This region also has an unusually high incidence of otherwise rare upper urothelial cancers. Between 1991 and 2002 the average general mortality for both sexes in the endemic region was 10.3 per thousand and the specific mortality for patients with EN was 0.65 per thousand (M 0.58/10((3)), F 0.72/10(3)). The average age of death of patients with EN was 69.2 years (M 67.7, F 70.3), which is similar to the life expectancy for the rest of the population in the county (67.8, M 64.4, F 71.8). This life expectancy is significantly higher than in the period 1957-1960 when the average age of EN-related death was 45.1 years. Between 1995 and 2002, in contrast to both Croatia as a whole and the respective county, the specific mortality with tumors of the pyelon and ureter in the endemic region was much higher in women than in men (9.020 and 4.697 per 100,000, respectively). The specific mortality of all patients with urothelial tumors was 14 times higher in the endemic region than in Brodsko-Posavska county and 55 times higher than in Croatia overall. The much higher specific urothelial-tumor mortality in women than in men (in contrast to the rest of the country) and the higher specific EN mortality indicate that the causative agent of the two nosological entities is the same.