A clinical phase III study of tropisetron capsule was conducted to assess its efficacy, safety and usefulness on nausea and vomiting induced by carboplatin or non-platinum anti-cancer drugs. The study was conducted in patients who experienced vomiting on previous chemotherapy. Tropisetron 5 mg capsule was given to patients once 2 hours prior to the first administration of either carboplatin or non-platinum anti-cancer drugs; the patients were then observed for nausea and/or vomiting during 24 hours after the first administration. Some 56.7% (17/30) of the patients did not vomit after tropisetron administration, and the frequency of vomiting was significantly reduced compared with that during the previous chemotherapy. Further, in the clinical efficacy ratings, in which the efficacy was assessed on the basis of the nausea and vomiting data, 83.3% (25/30) of cases were rated as "effective or better". Adverse events observed were 3 cases of mild headache, but these were not clinically problematic. The above results reveal that tropisetron capsule is significantly effective and safe in the treatment of nausea and vomiting induced by carboplatin or non-platinum anti-cancer drugs; in addition, tropisetron proved to be highly useful for its convenience as an oral agent.