Adult living donor liver transplantation (aLDLT) is associated with surgical risks for the donor and with the possibility of small-for-size syndrome (SFSS) for the recipient, with both events being of great importance. An excessively small liver graft entails a relative increase in the portal blood flow during reperfusion, and this factor predisposes the recipient to an increased risk of SFSS in the postoperative period, although other causes related to recipient, graft, and technical factors have also been reported. A hemodynamic monitoring protocol was used for 45 consecutive aLDLT recipients. After various hemodynamic parameters before reperfusion were analyzed, a significant correlation between the temporary portocaval shunt flow during the anhepatic phase and the portal vein flow (PVF) after reperfusion of the graft (R2 = 0.3, P < 0.001) was found, and so was a correlation between the native liver portal pressure and PVF after reperfusion (R2 = 0.21, P = 0.007). The identification of patients at risk for excessive portal hyperflow will allow its modulation before reperfusion. This could favor the use of smaller grafts and ultimately lead to a reduction in donor complications because it would allow more limited hepatectomies to be performed. Liver Transpl 19:174–183, 2013. © 2012 AASLD.