The antioxidant activities of tocotrienols are more robust than that of tocopherols. Palm oil is a rich natural source of tocotrienols. Heme oxygenase-1 (HO-1) is an enzyme that has antioxidant, anti-inflammatory and cytoprotective functions. The objective of this study is to determine the effects of different doses of TRF oral supplementation on HO-1 gene and protein expression in mice livers. Thirty male ICR white mice (25-30 g) were divided into five groups; three groups were administered TRF orally for 14 days at doses of 200, 500 and 1000 mg/kg respectively (n = 6 per group), a positive control group was administered 100 mg/kg butylated hydroxyanisole (BHA) orally for 14 days (n = 6), and a control group (n = 6) was only administered the vehicle (corn oil). At day 15, the mice were sacrificed and their livers isolated. Total RNA was extracted from the livers and quantitative real-time polymerase chain reaction (qPCR) assays were performed to analyse HO-1 gene expression. The livers were then homogenized and HO-1 protein expression was analysed by Western blotting. It was observed that TRF oral supplementation at concentrations of 200, 500 and 1000 mg/kg for 14 days resulted in significant concentration-dependent increase in HO-1 gene and protein expression in mice livers, compared to controls. In conclusion, TRF supplementation induced HO-1 gene and protein expression in mice livers dose-dependently, with the highest expression seen in mice receiving 1000 mg/kg TRF.