The aim of this phase II study was to determine the antitumour activity and safety of trans-1-diaminocyclohexane-platinum (oxaliplatin) in previously untreated advanced non-small cell lung cancer (NSCLC) patients. 33 patients with unresectable and measurable NSCLC were entered into this phase II study between January 1992 and January 1994. Patients had either locoregional disease with performance status 2 (19 patients) or a stage IV disease (14 patients). Oxaliplatin (130 mg/m2) was given on an out-patient basis (2-h infusion, every 21 days) without hydration. Response was assessed after every two courses. One hundred courses were administered, with a mean of three courses per patient (range 1-12). All patients were evaluable for response; 1 had a complete response, and 4 a partial response (overall response rate 15%, 95% confidence interval 5.1-31.9%). The median response duration was 5.9 months. All cycles (n = 100) were evaluable for toxicity assessment. Transient reversible, cold-related finger dysesthesias occurred in 29 patients, but were mild, and disappeared in most cases within a few days. We observed brief episodes of pharyngolaryngeal discomfort (8 patients, 11 episodes) accompanied in 4 cases (3 patients), by transient episodes of inspiratory stridor, leading 2 patients to treatment withdrawal. We conclude that oxaliplatin has activity in poor-prognosis NSCLC and that this treatment is feasible in out-patients; the absence of renal and haematological toxicity makes this drug a good candidate for further evaluation in NSCLC.