Thirty-five unselected postmenopausal women with metastatic breast carcinoma, refractory to hormonal manipulation and/or chemotherapy, were treated with vindesine (3 mg/m2 day 1, then weekly for 6 weeks, then every other week) and mitomycin (12 mg/m2 day 1, then every 6 weeks). Thirty-one patients were evaluable for response. Two patients obtained a complete response (CR), three patients a partial response. Duration of the response in the two patients with CR was 24 and 16 months, respectively. Toxicity was mild, consisting of leukopenia and neurologic toxicity. Thrombocytopenia was not a significant clinical problem. Vindesine with mitomycin C, as administered in this study, is a safe, but marginally effective regimen for previously treated patients with metastatic breast cancer.