A phase I evaluation of vindesine was carried out in 69 adult patient with advanced malignancies. Two escalating dose schedules were explored: (a) a single dose every 7--14 days, and (b) daily injections X 5--10 days as tolerated. The main toxic effects were myelosuppression, alopecia, paresthesia, asthenia, myalgia, and hyporeflexia. Antitumor activity was seen during this phase I study in patients with leukemia, lymphoma, and testicular neoplasms. Disease oriented phase II trials of 3--4 mg/m2 every 7--14 days or 1.3--2.0 mg/m2/day X 5--7 days every 3 weeks would be appropriate.