A phase II study of vindesine at a dose of 3 mg/m2 I.V. for 6 weeks and every other week thereafter was carried out in 18 patients with small-cell carcinoma of the lung. All patients were refractory to conventional therapy and all had been treated previously with spindle inhibitors, vincristine, or VP 16-213. All patients were evaluable for response and toxicity. No objective responses were observed. Leukopenia, the only hematologic toxicity, occurred in 13 patients (72%). Neurotoxicity occurred in five patients (28%). Vindesine appears to have limited activity in patients with small-cell carcinoma of the lung previously treated with spindle inhibitors.