A phase II evaluation of UFT, a mixture of tegafur and uracil, was performed in 13 patients with non-small cell lung cancer (eight patients with adenocarcinoma and five patients with squamous cell carcinoma). UFT at a dose of 600 mg was given per os every day for more than four weeks. Among 12 evaluable patients, one patient with adenocarcinoma of the lung showed partial response. The response rate for UFT was 8.3%. Toxic effects included anorexia (31%), nausea (15%), liver disorder (15%), and pigmentation (8%).