BACKGROUND: After liver transplantation, the daily cyclosporine dose is adjusted to maintain the blood level in a chosen range. The aim of this study was to assess the influence of liver graft injury on cyclosporine dose. METHODS: The parameters of liver function were investigated in 145 patients. Ninety-two patients took part in a longitudinal study. RESULTS: The cyclosporine dose correlated with the MEGX test (r=0.38, P=0.01) and with the ICG (r=0.38, P=0.0001) and BSP (r=0.37, P=0.0002) clearances; it had an inverse correlation with transaminases (AST: r=0.38, P=0.0001) and histological lesions (r=-0.29, P=0.005). The cyclosporine dose was lower in patients with recurrent hepatitis C (179+/-9 mg/day) than in those without (241+/-10 mg/day), and was lower in patients with chronic hepatitis (154+/-9 mg/day) than in those without (207+/-16 mg/day). In the longitudinal study, the percent variation of AST correlated inversely with that of cyclosporine dose (r=-0.62, P=0.0002). CONCLUSION: Progressive graft injury leads to a reduction in the cyclosporine dose, particularly in patients with recurrent hepatitis C.