The antioxidant and antihepatotoxic activities of a wood inhabiting macrofungus, Phellinus rimosus were studied. The superoxide anion scavenging, Fe(2+)-ascorbate induced lipid peroxidation inhibiting, hydroxyl radical scavenging and nitric oxide scavenging activities of the ethyl acetate extract were determined. The results indicated that ethyl acetate extract of P. rimosus exhibited significant in vitro antioxidant activity. The ethyl acetate extract of P. rimosus also showed potent antihepatotoxic activity against carbontetrachloride-induced acute toxicity in rat liver. The amelioration of liver toxicity by the ethyl acetate extract was evident from its significant effect on the levels of serum glutamate pyruvate transaminase (SGPT), serum glutamate oxaloacetate transaminase (SGOT) and serum alkaline phosphatase (ALP). The results suggest that hepatoprotective effect of P. rimosus is possibly related to the free radical scavenging activity.