The purpose is to determine the response to, and toxicity of docetaxel (Taxotère) in patients with inoperable non small cell lung cancer (NSCLC), previously untreated. Seventy patients with stage IIIB or IV NSCLC were treated by 100 mg/m2/ 3 weeks of docetaxel until tumor progression or severe toxicity. Premedication with diosmine and prednisolone was given in all patients: 66/70 were eligible and 55/70 were assessable for antitumoral activity. Median age: 63 years, WHO performans status 0-1: 83%, stage IV: 96%. For eligible patients, 17/66 (26%) achieved an objective response: 1 complete response and 16 partial response (IC 95% = 15-36). With a median follow-up of 23.4 months (range 14.9-28.7), for evaluable patients, the median response duration was 8 months, the median time to progression 4 months, and the median survival time 10 months. The median number of administered cycles is 5 (range 1-12). The estimate one year survival rate was 47%. Seventy-six patients presented neutropenia (grade 3-4); febrile neutropenia was observed in 7% of cycles. Non haematological toxicities are: fluid retention related to docetaxel (2.9%), diarrhea (6%), nausea-vomiting (4%), asthenia (3%), nail changes (6%). Docetaxel (Taxotère) administered at 100 mg/m2/3 weeks has relevant clinical activity in previously untreated NSCLC with a acceptable toxicity.