Aim: During liver regeneration cellular proliferation and apoptosis result in tissue remodeling to restore normal hepatic mass and structure. Main regulators of the apoptotic machinery are the Bcl-2 family proteins but their roles are not well defined throughout the liver regeneration. We aimed to analyze the expression levels of bcl-2gene family members during resection induced liver regeneration. Methods: We performed semi-quantitative RT-PCR to examine the expression level of bak, bax, bcl-2 and bcl-XL in 70% hepatectomized rat livers during the whole regeneration process and compared to that of the sham and normal groups. Results: The expression of bak and bax was decreased whereas that of bcl-2 and bcl-XL was increased in hepatectomized animals compared to normal liver at most time points. We also reported for the first time that sham group of animals had statistically significant higher expression of bak and bax than hepatectomized animals. In addition, the area under the curve (AUC) values of these genes was larger in sham groups than the hepatectomized groups. Conclusion: The expression changes of bak, bax, bcl-2 and bcl-XL genes are altered not only due to regeneration, but also due to effects of surgical operations.