This phase II clinical trial was conducted in a series of patients with advanced breast cancer, refractory to conventional chemotherapy. The therapeutic regimen consisted of a combination of cisplatin 100 mg/m2, given as a 24-hr infusion on day 1 and vindesine (VDS) 2 mg/m2, i.v. bolus on days 1 and 8. VDS injection was omitted on day 8 in patients with poor bone marrow reserves (prior extensive irradiation). Courses were repeated at 4-week intervals until documented disease progression. Among 46 evaluable patients, there were two complete and seven partial remissions for an overall response rate of 20%. These responses lasted for a median of 21 weeks (range 8-89 weeks). Remission rates according to the predominant metastatic site were as follows: soft tissue, 3/8 (38%); bone, 0/6 (0%); viscera, 6/32 (19%). Transient myelosuppression and gastrointestinal intolerance were almost universal. Renal function impairment and neurologic manifestations were frequently encountered but these adverse reactions were generally mild. Significant antineoplastic activity in far-advanced and heavily pretreated patients warrants further evaluation of this regimen at an earlier stage of the disease.