In this study we evaluated the antiemetic activity of a combination of 3 mg granisetron in a short i.v. infusion followed by 12 mg dexamethasone i.v. in 64 patients with cancer receiving moderately emetogenic chemotherapy scheduled in a single day. No patient had previously undergone chemotherapy and three consecutive cycles were evaluated. Response to antiemetic treatment was graded as follows: complete response, no episodes of vomiting; major response, only one episode; minor response, two to four episodes; failure, more than four episodes. Nausea was graded as absent, mild, moderate or severe (patients bedridden). At the first cycle a complete protection from acute vomiting and nausea was achieved in 95% and 73% of patients respectively; the rate of complete response for delayed vomiting was 90%, while 45% of patients complained of delayed nausea. The antiemetic and antinausea efficacy remained substantially unchanged during the second and third cycles of chemotherapy. Constipation and headache were the most frequent adverse events. In conclusion this antiemetic regimen appears very effective in preventing nausea and vomiting in moderately emetogenic chemotherapy.