The transition from regular use of cyclosporine to the newer calcineurin-inhibitors, such as tacrolimus, has been suggested as a contributing factor to the "era effect" of worsening outcomes of post-transplant HCV recurrence. This retrospective medical chart review of 458 patients was undertaken to evaluate the role of immunosuppressant choice (cyclosporine vs. tacrolimus) in determining virologic response and clinical outcomes of post-liver transplant HCV infection recurrence. Our results showed that patients undergoing interferon-based treatment taking cyclosporine have significantly better odds (OR: 2.59, P = 0.043) of presenting a sustained viral response (66.7%) compared to tacrolimus (52.8%). This did not result in a significant effect on post-liver transplantation clinical events including HCV-related deaths, graft loss, fibrosing cholestatic hepatitis, hepatocellular carcinoma or graft rejection. Other variables, which showed a significant relationship with the achievement of sustained viral response included donor age (OR 0.96, P = 0.001) and HCV genotype 1 infection (OR 0.05, P < 0.001). The observed significant increase in the odds of acute/hyperacute (OR 6.49, P = 0.001) and chronic rejection (OR 10.45, P < 0.001) in the cyclosporine to tacrolimus switch group, accompanied by an increase in the odds of HCV-related death (OR 2.30, P < 0.047) compared to tacrolimus merits further study. A significant increase (P < 0.044) in new-onset diabetes mellitus with tacrolimus (28.3%) compared to cyclosporine (18.7%) was also observed. Pre-transplant diabetes mellitus was associated with a significantly increased likelihood of graft fibrosis (HR 1.95, P = 0.003).