Size mismatching is a major concern in adult living donor liver transplantation (ALDLT). Graft hyperperfusion in these grafts is considered the main factor leading to graft dysfunction and poor survival. We describe the clinical significance of graft inflow modification (GIM) by splenic artery ligation in a series of 24 consecutive ALDLT. Between September 1999 and December 2001, 24 patients underwent ALDLT at our institution. Patients were divided into two groups: G1, n = 11 without GIM, and G2, n = 13 with GIM. Both groups were equivalent in terms of preoperative clinical state, graft characteristics, and surgical technique. Graft hyperperfusion was noticed overall, especially in small grafts (graft-to-recipient body weight ratio <0.8), with mean recipient portal vein (rPVF) values at least three times greater than those recorded in the donors. GIM permitted in G2 a significant decrease in rPVF. Small-for-size syndrome (SFSS) occurred in three (27%) patients in G1 with small grafts showing graft hyperperfusion and necessitating a retransplantation. SFSS did not occur in G2. One-year overall survival was 62% and 93% respectively for G1 and G2. It is concluded that when small-for-size grafts are accompanied by graft hyperperfusion, the rPVF should be lowered to avoid the SFSS and to improve the outcome.