Length of stay (LOS) is considered a reliable surrogate for liver transplant resource utilization. Little information exists about how donor and recipient variables interact to affect transplant LOS. Data for adult, non–status 1 transplants (1998–2005), including the donor risk index (DRI) and Model for End-Stage Liver Disease (MELD) scores, were collected from 2 institutions (n = 745 for center A and n = 710 for center B). Cox proportional hazards models identified variables associated with LOS for the separate and combined cohorts. The cohorts differed significantly in donor, recipient, and transplant factors. DRI (1.46 for center A and 1.40 for center B, P = 0.0013) and MELD (22.4 for center A and 20.4 for center B, P = 0.046) were both higher at center A, but LOS was comparable (13.7 days for center A and 13.3 days for center B, P = 0.052). Three factors at center A (nonlocal donor, recipient age, and MELD) and 7 factors at center B (donor age and weight, recipient female gender, retransplant status, international normalized ratio, MELD, and cold ischemia time) were associated with transplant LOS. For the combined cohort, donor age, weight, nonlocal status, recipient age, female gender, retransplant status, MELD, and transplant center were LOS risk factors. In conclusion, the impact of donor and recipient variables on LOS varies by institution. However, the MELD score exerts a potent and consistent effect across institutions, emphasizing the dominant role of disease severity in liver transplant resource utilization. Liver Transpl 15:1570–1578, 2009. © 2009 AASLD.