Lung cancer is frequent and serious. Squamous cell carcinomas, adenocarcinomas and undifferentiated non-small cell carcinomas account for 80 percent of all lung cancers. Patients with one or the other of these carcinomas and potentially curative surgical resection, but they represent only one quarter of all carcinomas. In patients with regionally more advanced carcinomas, notably when the mediastinal lymph nodes are invaded, surgical resection only results in a 5 to 15 percent survival rate at 5 years. At this stage of lung cancer, an effective cytostatic treatment may improve the survival rate, inasmuch as most therapeutic failures are due to metastatic progression. Neoadjuvant (preoperative) chemotherapy is now undergoing evaluation by controlled trials. This therapeutic strategy rests on two arguments: 1) patients treated with chemotherapy for locally advanced lung carcinomas may subsequently benefit from complete resection in over 50 percent of the cases; 2) neoadjuvant chemotherapy might sterilize the subclinical metastatic disease at the time of diagnosis. Studies are in progress to evaluate the effectiveness of neoadjuvant chemotherapy in terms of survival. Until the final results are available, this treatment cannot be proposed as a consensual therapeutic solution, but feasibility studies are encouraging.