Interferon alfa in dose 3-6 MU IM was administered during six months 3 times per week in 30 children with chronic hepatitis C with leukaemias and lymphomas. Chronic hepatitis was diagnosed basing on anti-HCV, RNA HCV by PCR, high activity of ALT and histopathologic examination of the liver. The patients were followed-up for 12 months after IFN therapy. Sustained normalization of ALT levels, together with serum HCV RNA elimination was considered as a complete response and achieved in 33% children. Partial response (ALT normalization without serum HCV RNA elimination) was recorded in 57% patients. Anti HCV antibody was detected in all children during the time of observation.