Currently, only a few chemotherapeutic agents have consistently produced single agent response rates greater than 15% in patients with non-small-cell lung cancer (NSCLC). Taxol has been reported in two phase II studies to have significant activity in NSCLC with response rates of 21% and 24%. Schedule infusion of 24 hours has been used to reduce allergic reactions. The study reported here was a phase II trial of Taxol given by 3-hour intravenous infusions at a 210 mg/m2 dose every three weeks in outpatients setting. It was conducted simultaneously at three centers on chemotherapy-naïve patients medicated with unresectable stage III or metastatic NSCLC. Sixty-two patients were initially enrolled; all were premedicated with dexametasone (20 mg), cimetidine (330 mg) and diphenilhydramine (50 mg), given prior to initiation of paclitaxel infusion. Fifty patients were evaluated for toxic effects and 47 for response. Sixteen partial responses (34) and one complete response (2%) were observed, for an overall response rate of 36% (95% confidence internal, 22% to 50%). Taxol was well-tolerated and none of the patients experienced allergic reaction. Granulocytopenia was generally mild. Therapy was interrupted in only two patients because of the development of grade 3 neuropathy. In our experience Taxol is one of the most active cytotoxic drugs targeting non-small-cell lung cancer.