The aim of this study was to evaluate the influence of preserving the recipient's inferior vena cava during orthotopic liver transplantation (OLT) on hemodynamic alterations, blood component requirements, postoperative liver and renal function, as well as vascular-related complications. A total of 122 OLTs was studied. In 35 OLTs, venovenous bypass (BP) was used; in 35 OLTs, bypass was not used (NBP); and in 52 OLTs, the recipient's inferior vena cava was preserved (PC). Preservation of the inferior vena cava means that venous return is not compromised at any time during transplantation. The time of hepatectomy was not different among the three groups (208 +/- 11, 188 +/- 13, and 194 +/- 6 minutes for BP, NBP, and PC, respectively); however, the total operating time was significantly lower in PC patients (492 +/- 24, 459 +/- 18, and 419 +/- 10 minutes for BP, NBP, and PC, respectively; P = .004, ANOVA). Blood component requirements were significantly lower in patients with PC. For red blood cells, these were 15.2 +/- 2.6, 16 +/- 3.4, and 7.1 +/- 1.5 units for BP, NBP, and PC, respectively (P = .009, ANOVA), and for fresh-frozen plasma, these were 5.4 +/- .7, 5.8 +/- .9, and 3 +/- .4 L for BP, NBP, and PC, respectively (P = .005, ANOVA). Postoperative liver and renal function did not differ among the three groups. The incidence of surgical complications (bleeding and vascular) was similar. Preservation of the inferior vena cava of the recipient significantly reduces the magnitude of OLT.