The effects of annatto seeds and of bixin on the oxidative damage induced by cisplatin in male Wistar rats was evaluated in the present study by way of lipid peroxidation, weight gain, the food efficiency coefficient, fat deposits in the hepatocytes and dosing of the enzymes in this organ. The animals were divided into four groups: control group (CG), cisplatin group (CPG), bixin+cisplatin group (CBG) and annatto+cisplatin group (CUG). Cisplatin (5 mg/kg body weight) was injected intraperitoneally 48 hours before the end of the experiment. The bixin and annatto were administered daily together with the commercial feed. The pre-treatment with annatto and bixin attenuated the cisplatin-induced liver damage and significantly reduced the enzymes AST and ALT. Annatto was shown to be capable of inhibiting lipid peroxidation as determined by TBARS. These results suggest that annatto seeds and bixin could be important agents in the reduction of cisplatin-induced hepatotoxicity.