The preventive effect of propolis extract on D-galactosamine-induced hepatic injury was examined in rats. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities were significantly increased at 24 h after intraperitoneal injection of D-galactosamine (400 mg/kg) in the animals. Propolis extract was administered orally three times in doses of 3 or 30 mg/kg at 18 h and 1 h before and 8 h after D-galactosamine injection. The extract itself and the vehicle alone (dextran) caused no significant changes in serum AST or ALT activities. Treatment with the extract dose-dependently prevented the increases in serum AST and ALT activities induced by D-galactosamine, and significant inhibition was observed at a dose of 30 mg/kg. These results suggested that propolis extract may have an ameliorating effect on hepatic dysfunction.