Chimpanzees were used in hepatitis research for over three decades with the aim to identify and develop treatments for the virus, a leading cause of chronic liver disease in humans. We used a dataset of 120 chimpanzees housed at a single institution in Japan, 22 of whom became chronically infected with hepatitis C virus (HCV), to examine whether HCV infection results in a reduced lifespan as reported in humans. Survival analysis showed that HCV carriers experienced a higher mortality risk compared with non-carriers. Although no chimpanzee died from hepatic disease, carriers showed higher gamma-glutamyl transpeptidase (γGTP) levels compared with non-carriers suggesting that HCV infection negatively affected their liver condition. These results provide evidence that special attention is necessary to monitor the long-term condition of ex-biomedical primates.