There has recently been a marked trend to increasing dose intensity in cancer chemotherapy, with or without peripheral blood stem-cell support, which has been associated with a higher frequency of nausea and vomiting. Antiemetic treatment in this setting has not been extensively analysed. From October 1995 to January 1997, prevention of emesis with granisetron 3 mg/12 h i.v., dexamethasone 12 mg/24 h i.v., haloperidol 0.5 mg/12 h p.o., and loracepam I mg/24 h p.o. was instituted in 30 breast cancer patients treated with high-dose chemotherapy (a 4-day intravenous continuous infusion of cyclophosphamide 1500 mg/m2 per day, thio-TEPA 125 mg/m2 per day and carboplatin 200 mg/m2 per day).A total of 30% of the patients (9/30) obtained complete or major protection on the 4 days of chemotherapy treatment (96.7% (29/30) on day 1, 86.7% (26/30) on day 2, 70% (21/30) on day 3, and 50% (15/30) on day 4). On the days following chemotherapy, 46.7% (14/30) presented fewer than two emetic episodes on day 5, 70% (21/30) on day 6, 83.4% (25/30) on day 7 and, 93.3% (28/30) on day 8. This energic antiemetic combination treatment has hardly any effect in the prevention of emesis, providing complete or major protection of 30% for the 4 days of chemotherapy treatment. Further investigation aimed at improving antiemetic treatment results is necessary.