The objective of the study was to examine the problem of control of nausea and vomiting induced by non-cisplatin cyclophosphamide-based chemotherapic regimens in breast cancer patients.This was a randomized double-blind, parallel-group and placebo controlled study comparing the efficacy of four antiemetic therapeutic regimens (A:Ondansetron for 3 days; B:Ondasetron plus Metoclopramide; C:Granisetron given a single dosis and D:Ondansetron given in a single dosis) in breast cancer patients receiving Cyclophosphamide, Methotrexate and 5-Fluoracil (CMF) regimen (174 cycles) and Cyclophosphamide, 4-Epiadryamicin and 5-Fluoracil (FEC) regimen (132 cycles). Both, number of emetic episodies (early and delayed emesis) and quality of life were evaluated.In patients receiving CMF there were no differences between regimens A, B and C in controlling early emesis. The single dose Ondansetron regimen (D) showed the worst resuts (p=0.003). Delayed emesis was best controlled by the “3 days-regimens” (A and B). In patients administered a FEC treatment, the antiemetic efficacy was superior for the single Granisetron regimen (C) if early emesis was considered. Moreover, efficacy of single Granisetron dosis (C) was similar to the 3-days Ondansetron regimen (A) in controlling delayed emesis after FEC treatment. The single Ondansetron regimen showed again the worst results (p=0.007).Despite different antiemetic schedules, nausea and emesis are significant problems in patients receiving cyclophosphamide-based chemotherapy.