Background. Hepatic artery thrombosis (HAT) is a significant cause of morbidity after liver transplantation. The aims of this study are to identify and compare risk factors that might contribute to HAT. Methods. A total of 424 liver transplants performed at the University of Virginia were reviewed. HAT was defined as complete disruption of arterial blood flow to the allograft and was identified in 29 cases (6.8%). HAT was classified as early (less than 1 month posttransplant, 9 cases: 2.1%) or late (more than I month posttransplant, 20 cases: 5.4%). Possible risk factors for HAT were analyzed using Pearson χ2 test for univariate analysis and logistic regression for multivariate analysis. Results. Multiple transplants, recipient/donor weight ratio >1.25, biopsy-proven rejection within 1 week of transplant, recipient negative cytomegalovirus (CMV) status, arterial anastomosis to an old conduit (defined as a previously constructed aorto-hepatic artery remnant using donor iliac artery), and CMV negative patients receiving allograft from CMV positive donors were found to be significant risk factors for developing early HAT. After logistic regression, factors independently predicting early HAT included arterial anastomosis to an old conduit [odds ratio (OR) =7.33], recipient/donor weight ratio > 1.25 (OR=5.65), biopsy-proven rejection within 1 week posttransplant (OR=2.81), and donor positive and recipient negative CMV status (OR=2.66). Female donor, the combination of female donor and male recipient, recipient hepatitis C-related liver disease, donor negative CMV status, and the combination of recipient CMV negative and donor CMV negative were found to be significant risk factors for late HAT. Factors independently predicting late HAT by logistic regression included negative recipient and donor CMV status (OR=2.26) and the combination of a female donor and male recipient (OR=1.97). Conclusion. Therefore, in nonemergency situations attention to these factors in donor allocation may minimize the possibility of HAT.