To evaluate the prevalence of HBV, non-A, non-B hepatitis (NANBH) and HCV, their evolution and the route of transmission, we performed a retrospective study (17 years) on 65 hemodialyzed patients (mean dialytical age 5 years, range 1-16) who developed acute viral hepatitis. Twenty-six percent of them were affected by HBV; 5 of them (29%) became chronic. Fourty-eight of 65 patients were affected by NANBH; in 1990,42 of them were tested for antibody to HCV with the C-100 Elisa assay: 27 patients (64%) were positive. Seven of 27 patients demonstrated normal values of ALT. The evaluation of intrafamiliar transmission of HBV showed 8 sexual partners infected. In the family, no one was anti-HCV positive. In agreement with the current literature, we have observed: (1) a decrement in HBV infection; (2) that HCV is the major cause of NANBH; its rate of chronicity is over 50%; (3) that the prevalent mode of HCV transmission is the parenteral route while the sexual route seems to be negligible.