OBJECTIVE 5-fluorouracil given by continuous infusion allows higher dose delivery, causes less myelosuppression and may interfere with repair of DNA damage caused by carboplatin. With this rationale, we conducted a phase II study to test the activity and toxicity of 5-fluorouracil and carboplatin given in continuous infusion to patients with advanced cancer and pretreated with at least two chemotherapy regimens. METHODS Forty patients with advanced tumors (21 colon, 4 stomach, 3 breast, 3 bladder, 3 ovary, and 6 at other sites) were entered in the trial. 5-fluorouracil (200 mg/m2) and carboplatin (20 mg/m2) were administered by continuous infusion from days 1 to 20, every 4 weeks. RESULTS All patients were assessable for response and toxicity. A total of 138 courses of chemotherapy were administered, with a mean of 3.5 per patient (range, 2-9). Toxicity, assessed using WHO criteria, was as follows: nausea and vomiting grade 2-3 in 34% of patients, alopecia grade 2-3 in 96%, and neutropenia grade 3-4 in 26%. One patient (2.5%) had a complete response to therapy and 7 (17.5%) had a partial response (response rate 20%; 95% Cl, 9.06-35.68%). Disease stability and progression occurred in 12 (30%) and 20 (50%) patients, respectively. Median time to progression was 5.6 months (range, 2.8-45.9+), with a median survival time of 7.7 months (range, 1.5-45.9+). CONCLUSIONS Outpatient treatment with a combination of 5-fluorouracil and carboplatin in continuous infusion was active as salvage treatment for advanced tumors and may give prolonged palliation of symptoms with manageable toxicity.