The aim of this study was to determine the tacrolimus blood levels in recipients of living donor liver transplants (LDLT) compared with recipients who undergo whole cadaveric liver grafts and to correlate the tacrolimus trough levels with the 12-hour area under the concentration (AUC) curve. From June 2002 to June 2003, the 10 LDLT were prospectively compared with 11 cadaveric transplants. The main immunosuppression was tacrolimus plus steroids. Intraoperative methylprednisolone was administered to all cadaveric organ recipients and only 6 of the 10 LDLT. Median tacrolimus trough levels at day 10 were 14.1 ng/mL for the LDLT group and 9.1 ng/mL for the CLT group (P = NS). The median tacrolimus AUC at day 10 were 185.2 ngxh/mL and 148.1 ngxh/mL for the LDLT group and the cadaveric group, respectively (P = NS). Median tacrolimus trough levels at day 2 were 24.3 ng/mL versus 9.9 ng/mL in the LDLT recipients with and without steroids, respectively (P < .05). Also, median tacrolimus AUC at day 2 were 239 ngxh/mL and 179.7 ngxh/mL when we compared LDLT recipients with and without steroids (P = NS). A significant correlation was observed between tacrolimus trough levels and AUC in the LDLT group (C.C. = 0.936; P < .0001). In conclusion, LDLT recipients display higher tacrolimus blood levels in comparison with cadaveric liver recipients, with a good correlation between tacrolimus trough levels and AUC. Intraoperative steroid administration induces higher tacrolimus levels in LDLT recipients.