Determinants of progression to cirrhosis in hepatitis C virus (HCV) infection have been well described in the immunocompetent population but remain poorly defined in liver transplant (LT) recipients. This cohort study determines the factors contributing to the development of fibrosis and its rate of progression in the allograft. Predictive factors analyzed include: demographics, host and donor factors, surgery-related variables (cold and warm ischemia time), rejection episodes, cytomegalovirus infection (CMV), and immunosuppression. Over 12 years, 842 adult LTs were performed at our institution; 358 for the indication of HCV. A total of 264 patients underwent protocol liver biopsies at month 4 and yearly after LT. Using the modified Knodell system of Ishak for staging fibrosis, the median fibrosis progression rate was .8 units/year (P < .001). Rapid fibrosis progression (> .8 units/year) was best identified by liver histology performed at 1 year. Donor age > 55 years was associated with rapid fibrosis progression and development of cirrhosis (P < .001). In contrast, donor age < 35 years was associated with slower progression of fibrosis (P = .003). Risk factors for graft loss due to recurrent HCV included recipient age > 35 years (P = .01), donor age > 55 years (P = .005), and use of female donor allografts (P = .03). In conclusion, fibrosis progression in HCV-infected LT recipients occurs at a rate of .8 units/year. Increased donor age has a major impact on disease progression, graft failure, and patient survival. A liver biopsy performed at 1 year posttransplant can help identify those patients more likely to develop progressive disease and may allow better targeting of antiviral therapy.