Nude mice transplanted with a human tumor of the larynx were treated by combination therapy with UFT and carboplatin (CBDCA) for a prolonged period (3 months). To compare the combination therapy with UFT or CBDCA treatment alone, the mice were divided into four groups; control group, group orally given UFT (20mg/kg, five times a week for 3 months), group intraperitoneally given ip CBDCA (50mg/kg, every 3 weeks for 3 months), and group given combination therapy with UFT and CBDCA. No antitumor effect was observed in the group received UFT or CBDCA alone, while a significant antitumor effect was noted in the combination therapy group, compared to the control as evidenced by DNA histogram, showing a decrease in atypical cell count. The results of this study suggest that the combination of UFT and CBDCA provides an efficacious chemotherapy for cancers of the head and neck.