Continuous infusion 5-fluorouracil (CI 5-FU) and the combination of cisplatin (CDDP) plus etoposide (VP-16) have emerged as salvage regimens for metastatic breast carcinoma (MBC). In this study, 18 patients (15 with MBC) were entered into a Phase I study to determine the maximum intermittent doses of CDDP and VP-16 that could be added to 200 mg/m2/d CI 5-FU. The maximum tolerated dose of the combination was 40 mg/m2 of CDDP and 60 mg/m2 of VP-16 weekly for the first 8 weeks and every other week thereafter. The dose-limiting toxicities of the regimen were myelosuppression and thrombocytopenia. Two complete responses (both patients had received no previous chemotherapy) and one partial response were noticed. This regimen at the doses described here is appropriate for Phase II trials as an alternative to doxorubicin-based regimens for MBC.