Twenty-four previously treated patients with refractory or relapsed small cell lung cancer (SCLC) were entered into a prospective, multicenter phase II study. All 24 patients had been pretreated with some form of cisplatin-based chemotherapy. The median time of chemotherapy was 4.2 months (range 1.4–9.4 months). Patients were treated with a dose of 25 mg/m2 of vinorelbine weekly. Twenty-four patients were eligible for response and for toxicity. Partial response was observed in 3 out of 24 eligible patients (12.5%; 95% confidence interval, 2.7–32.4%). All 3 patients who responded had previous chemotherapy including vincristine. The most common toxicity was leukopenia (91.7%, 66.7% in WHO 3-4 grade) and anemia (70.8%, 20.8% in WHO 3 grade). Nonhematological toxicities were moderate and mild. These results support a two-stage sequential study design of previously untreated patients for further phase II study in SCLC.