HGV was discovered in 1995. It belongs to Flaviviruses and it is found worldwide. At first it was though to cause chronic hepatitis, in fact its pathogenicity is up till now unclear. The aim of this work was to estimate the prevalence of anti-HGV antibodies among children suffering from chronic hepatitis B (CHB), chronic hepatitis C (CHC) and chronic hepatitis B + C (CHB + C) and to compare it with the prevalence in healthy children in the district of Lodz, Poland, and to assess the influence of HGV infection on biochemical and histological parameters of chronic liver disease. PATIENTS AND METHODS. 153 children with chronic hepatitis B and C and 22 healthy children have been investigated. The presence of anti-HGV was assessed by ELISA. In children with chronic hepatitis prior the entrance to the study HCV-RNA, HBsAg, HBeAg, and if HBeAg-negative also HBV-DNA were assessed. Thick needle percutaneous liver biopsy was performed in each case. RESULTS. Of 153 children with chronic hepatitis, 17 (11%) were anti-HGV positive. Anti-HGV positivity was found in 3 (3%) of 94 children with CHB, 12 (25%) of 48 children with CHC, and 2 (18%) of 11 children with CHB + C. Anti-HGV were not found in any of 22 healthy children. Previous HGV infection was associated with CHC (p = 0.0001), history of hospitalization (p = 0.002) or blood transfusion (p = 0.0006) as compared with children with CHB. Serum albumin or gamma globulin concentration as well as ALT level or degree of inflammation and fibrosis in liver biopsy specimen were not correlated with previous HGV infection.