Aim: Atrophy/Hypertrophy complex constitution (AHC) by portal vein ligation (PVL) before major hepatectomies (Hx) has got beneficial effects on the functional capacity of the remnant liver tissue by increasing its volume. We aimed to evaluate whether longer duration of PVL has any additive benefit on regenaration speed, weight, biochemical, histological examination and mortality, before major hepatectomies in rats. Methods: One-hundred and twenty Wistar Albino rats were divided into four groups (PVL, PVL+Hx, Hx, Sham+Hx). Group I ( PVL ), Group II ( PVL + Hx ); 70% Hx and relaparotomy after 21 days from PVL, Group III ( Hx ); 70% Hx, Group IV ( Sham + Hx); 70% Hx after 21 days from Sham ligation. Hepatic tissue regeneration speed, weight, liver function tests and histological examination were evaluated on postoperatively 3rd , 7th , 14th and 21st days. Also, mortality rate was evaluated. Results: The regeneration speed increased in all groups except PVL+Hx. The weight of all rats decreased on postoperative 3rd day, however, then reached nearly preoperative values on 7th day and the higher values were seen on 28th day in all groups. Serum alkaline phosphatase levels increased in all groups postoperatively and decreased to normal values on postoperative 7th day. Mitosis has been seen until 3rd day in Hx, and Sham+Hx, until 14th day in PVL, and not in PVL+Hx. 1, 6, and 7 rats were lost in PVL+Hx, Hx, and Sham+Hx groups respectively in first three days. Mortality rates were significantly lower than Hx and Sham+Hx groups in PVL and PVL+Hx groups Conclusion: In this study the lesser liver tissue had to be resected in rats constituted AHC with long term PVL, so we had more remnant liver tissue to be able to have enough function. The lengthening of the duration of PVL will be better for decreasing morbidity and mortality of major hepatectomies in benign liver pathologies