Background/Introduction Ischemic preconditioning is a method in which brief periods of ischemia render tissues resistant to injury resulting from prolonged ischemia and reperfusion, so-called ischemia–reperfusion injury. Purpose To elucidate the possible protective role of ischemic preconditioning in rat livers with ischemia–reperfusion injury. Methods Rats were first allocated to either a sham control or an ischemic preconditioning group. On the following day, the rats from each group were administered either 30 minutes or 45 minutes hepatic ischemia. Next, rat livers were harvested for measuring proliferating cell nuclear antigen, heme oxygenase-1, inducible nitric oxide synthase, and heat shock protein 70 mRNA levels. Results Both proliferating cell nuclear antigen and hemeoxygenase-1 expression increased significantly after 45 minutes hepatic ischemia compared with those after 30 minutes hepatic ischemia, but they decreased significantly with ischemic preconditioning. However, ischemic preconditioning did not affect inducible nitric oxide synthase or heat shock protein 70 expression. Conclusion From the preliminary findings, further elucidation is warranted.