A five-drug combination, including metoclopramide, thiethylperazine, diphenhydramine, dexamethasone, and diazepam, was given to 32 patients during three consecutive treatments with chemotherapy. Eighteen patients (group A) were treated with a cisplatin-containing regimen, and 14 patients (group B) were treated with a cyclophosphamide- and doxorubicin-containing chemotherapy. In group A, complete responses were lower on the first day than on the second and third days (P < 0.015 and P < 0.041, respectively), during the first and second courses. The five-drug antiemetic regimen seems safe and effective. These results show that clinical trials that evaluate antiemetic efficacy in cisplatin-containing chemotherapy regimens should evaluate at least two consecutive courses.