A role for vinblastine (VBL) in lung cancer has never been clearly defined. Because of recent pharmacokinetic data suggesting a biweekly schedule for VBL and recent antitumor activity shown for vindesine, a phase II trial of divided-dose VBL was initiated. Among 22 evaluable patients, a 27% major response rate was seen, with a median duration of 5.5 months (range 3.5-12+). The major toxic effect was myelosuppression but was easily manageable and tolerated. These results suggest schedule dependency for VBL and open the question of its efficacy in lung cancer.