Hepatic osteodystrophy is common side effect among patients with chronic liver diseases. It can be observed both in parenchymatous and in cholestatic liver diseases. According to WHO’s data approximately 3 % of world’s population (around 170 milion) is infected, more than 700 thousands in Poland. The aim of the study was to analyze the bone mineral metabolism status among patients with hepatitis C and compare it with patients without hepatitis C. The second aim was to evaluate the impact of 48 week lasting therapy with interferon alpha and ribavirin on the bone mineral metabolism status among patients with chronic hepatitis C. Bone mineral metabolism parameters were studied at 100 patients with chronic hepatitis C, aged 20 to 50 years old, and at 50 patients without hepatitis C. 25 patients with hepatitis C, who were treated with interferon alpha plus ribavirin during 48 weeks were analyzed 2 times - before and after this therapy. All the patients were measured serum total and ionized calcium, phosphorus, acid phosphatase, 25(OH)D3, intact parathyroid hormone (i-PTH), CTX, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, gamma-glutamyl transpeptidase (GGTP), cholinesterase, bilirubin, protein fraction pattern, prothrombin time. Results of our analyses showed lower levels of serum calcium and phosphorus among patients with hepatitis C comparing to the patients without this infection, which caused increased 25(OH)D3 level. The differences which were observed, was not so intense, that should required prophylactic farmacotherapy. The level of i-PTH and acid phosphatase were in normal ranges and level of CTX was not increased in the group of patients with hepatitis C comparing with control group. Moreover we found no effect of 48-week interferon alpha plus ribavirin therapy on the bone mineral metabolism status among patients with chronic hepatitis C.