The soft, gelatin capsule of VP-16-213 (etoposide) was given orally and evaluated in a Phase II study of 56 patients with histologically confirmed small cell lung cancer. The drug was given in a dose of 200 mg/body/day orally for 5 consecutive days, and the courses were repeated every 3 to 4 weeks depending upon the individual patient recovery from myelosuppression. An overall objective response was obtained in 17 patients (30%), five previously treated (23%) and 12 untreated (35%). The median days for response after the start of treatment was 14 d (range, 5 to 64), and the median duration of response was 62 days (range, 28 to 278). The dose-limiting factor was leukopenia, while thrombocytopenia was also experienced. Gastrointestinal reactions to toxicity and alopecia were also observed, but they were not overwhelming. The study demonstrated that the VP-16-213 soft gelatin capsule given orally is effective against small cell lung cancer without clinical cross-resistance to other cytotoxic agents. Its usefulness in combination chemotherapy is thus suggested.