Purpose: The aim of this study is to evaluate the neuroprotective effect of antioxidant supplementation with vitamin E in patients treated with cisplatin chemotherapy. Methods: Between April 1999 and October 2000, forty-seven patients were randomly assigned to either group one, which received vitamin E supplementation during cisplatin chemotherapy, or to group two, which received cisplatin chemotherapy alone. Alpha-tocopherol (vitamin E; 300 mg/d) was administered orally before cisplatin chemotherapy and continued for 3 months after the suspension of treatment. For preclinical studies, nude mice carrying the human melanoma tumor were treated with cisplatin alone or in combination with vitamin E. Results: Twenty-seven patients completed six cycles of cisplatin chemotherapy: 13 patients in group one and 14 patients in group two. The incidence of neurotoxicity was significantly lower in group one (30.7%) than it was in group two (85.7%; P < .01). The severity of neurotoxicity, measured with a comprehensive neurotoxicity score based on clinical and neurophysiological parameters, was significantly lower in patients who were supplemented with vitamin E than in patients who were not supplemented with vitamin E (2 v 4.7, P < .01). The results of the preclinical studies showed that when cisplatin was combined with vitamin E, no differences were observed in tumor weight inhibition, tumor growth delay, or life span as compared with treatment with cisplatin alone. Conclusion: Supplementation of patients receiving cisplatin chemotherapy with vitamin E decreases the incidence and severity of peripheral neurotoxicity.