Puncture biopsy of the liver and blood count were made in 72 patients with chronic hepatitis C (CHC). Morphological alterations in the liver were assessed by Knodell index. The blood serum, lymphocytes and hepatic tissue were examined for a genome form of hepatitis C virus (HCV) RNA, blood lymphocytes and hepatic tissue--for a relevant replication form. HCV RNA was detected using "nested" RT-PCR. Only 26% patients had symptoms of asthenovegetative and dyspeptic syndromes. Normal alaninaminotransferase (ALT) level was observed in 24% patients, the rest had it high. HCV RNA was encounted more frequently in hepatic tissue than lymphocytes or serum (83, 68 and 46%, respectively). A replication form of HCV RNA was present in hepatic tissue of 31% patients and was absent in the lymphocytes. The incidence of the RNA detection was not related either to the disease symptoms or morphological alterations in hepatic tissue. The occurrence of the genome and replication forms in hepatic tissue does not correlate to ALT level. HCV RNA occurs more often in the serum, blood lymphocytes and in three substrates simultaneously in patients with hyperalatemia.