The aim of the study was to evaluate the character of lesions within oral mucosa in patients suffering from chronic hepatitis and cirrhosis of the liver due to either HBV or HCV infection. A total of 74 patients treated at the Clinic of Infectious Diseases in Wrocław for chronic hepatitis B (20 patients, group I) and for chronic hepatitis C (23 patients group III) and cirrhosis of the liver due to HBV (15 patients , group II) and HCV (16 patients, group IV) infection. The control group comprised 29 healthy subjects. Lesions within the oral mucosa found on clinical examinations were confirmed with a histopathological evaluation. Patients suffering from chronic hepatitis B revealed leukoplakia (1/20), melanoplakia (1/20), petechiae (1/20), 17 patients from this group did not show any changes. Patients suffering from chronic hepatitis C revealed leukoplakia (6/23), Delbanco's disease (2/23), melanoplakia (1/23), lichen planus (1/23), petechiae (1/23), 12 patients from this group did not show any changes. Patients suffering from cirrhosis of the liver due of HBV infection revealed leukoplakia (3/15) petechiae (2/15), Delbanco's disease (1/15), angular cheilitis (1/15), aphthae (1/15), 7 patients from this group did not reveal any changes. Patients suffering from cirrhosis of the liver due of HCV infection revealed petechiae (2/16), melanoplakia (1/16), candidosis (1/16), labial herpes (1/16), 11 patients from this group did not reveal any changes. In control group we observed leukoplakia (3/29), Delbanco's disease (1/29), labial herpes (1/29), petechiae (1/29), and 23 subjects did not present pathological lesions within the oral mucosa. Results indicate the lack of connection between chronic HBV and HCV infection as well as the stage of the disease with the incidence and character of oral lesions in oral mucosa.