Tear fluid from 51 patients with chronic hepatitis C virus (HCV) infection was analyzed for the presence of the hepatitis C RNA to assess the potential role of this fluid in virus transmission. HCV sequences were amplified from sera and tear fluids by nested polymerase chain reaction using primers from the 5' non coding region of the virus genome. Positive samples were genotyped by the LiPA procedures. HCV RNA was detected in 76.5% (39/51) of the sera and in 9.8% (5/51%) of the tear fluid samples. The presence of the RNA in the tear fluid was independent of the severity of the hepatitis and of the viral load as measured by the branched DNA assay. The genotypes of the tears and serum isolates were different for two patients. For another patient, the HCV RNA was positive in the tear sample but negative in the serum sample. These findings suggest that tear fluid may transmit HCV but the source of HCV RNA in this fluid needs to be better understood.