Locally advanced non-small cell lung cancers have a poor prognosis following surgery alone when this has been possible, because of a high rate of local and metastatic relapses. Probability of five years survival for these patients ranges between 5 and 15%. Thus, locally advanced non small cell lung cancer for which resection is potentially possible but poorly curative are usually designated as marginally resectable. Adjuvant postoperative chemotherapy or radiation therapy hardly seem to improve survival. Therefore, other combined modality treatments might be proposed. Neoadjuvant chemotherapy may be used for non small cell lung cancer in an attempt (a) to improve complete resection rate and (b) to treat non-detectable metastatic disease. Numerous phase II studies have demonstrated the faisability of this combined modality in locally advanced non small cell lung cancers, particularly in stage N2 patients. Until the results of the ongoing phase III studies would be known, neoadjuvant chemotherapy might be considered as an investigational approach.