As the incidence of primary lung cancer in women seems to be increasing in parallel with that of smoking, we conducted an exhaustive epidemiological study in 137 hospitals in 2000. We identified 904 women with proven primary lung cancer (mean age 63.9 years), many of whom have never smoked (32.3%), particularly in cases of adenocarcinoma (43.4%). Small cell cancer accounted for 16.1% of cases. Adenocarcinomas were the most frequent (45.3%) of the non-small cell lung cancer (NSCLC), followed by squamous cell (23.4%), large cell (11.6%) and bronchoalveolar (1.9%) carcinomas. About one third (32.2%) of NSCLC were stage III and 48.1% were stage IV. Over half of all adenocarcinomas were stage IV. According to multivariate analysis, adenocarcinoma is related to less smoking and younger age. In conclusion, many women affected by lung cancer have never smoked. Adenocarcinoma appears to be the most frequent form and more often at a metastatic stage.