The aim of the study was to compare our reference adjuvant chemotherapy, FEC100 (fluorouracil 500 mg m(-2), epirubicin 100 mg m(-2) and cyclophosphamide 500 mg m(-2), six cycles every 21 days), to an epirubicin-vinorelbine (Epi-Vnr) combination for early, poor-prognosis breast cancer patients. Patients (482) were randomised to receive FEC100, or Epi-Vnr (epirubicin 50 mg m(-2) day 1 and vinorelbine 25 mg m(-2), days 1 and 8, six cycles every 21 days). The 7-year disease-free survival rates were 59.4 and 58.8%, respectively (P=0.47). The relative dose intensity of planned epirubicin doses was 89.1% with FEC100 and 88.9% with Epi-Vnr. There were significantly more grades 3-4 neutropenia (P=0.009) with Epi-Vnr, and significantly more nausea-vomiting (P<0.0001), stomatitis (P=0.0007) and alopecia (P<0.0001) with FEC100. No cases of congestive heart failure were reported, whereas four decreases in left ventricular ejection fraction occurred after FEC100 and five after Epi-Vnr. One case of acute myeloblastic leukaemia was registered in the FEC100 arm. After 7 years of follow-up, there was no difference between treatment arms. Epi-Vnr regimen provided a good efficacy in such poor-prognosis breast cancer patients, and could be an alternative to FEC100, taking into account respective safety profiles of both regimens.