In the study we described severe adverse events such as sepsis and bacterial endocarditis in the patient treated because of chronic hepatitis C (CHC). A case of 57 year old man with CHC, with recurring increased aminotransferases up to 100 IU/l; histological result of liver biopsy--G3, S2, HCV-RNA positive, genotype--HCV1b. The therapy with peginterferon alfa and ribavirin was introduced. The negative result of HCV RNA was obtained in 12th week of treatment. In the 7th month the patient was admitted to the hospital because of sepsis due to Escherichia coli, acute renal insufficiency and right orchitis. In spite of the treatment and general clinical improvement, the patient was still febrile. The bacterial endocarditis was found after number of diagnostic procedures. The treatment of endocarditis lasted 6 weeks in the hospital. During the hospitalization and 6 months after the HCV-RNA were performed with the negative results. The therapy of CHC with peginterteron and ribavirin is save in most cases however requires increased clinical surveillance, especially in the second half-year.