Therapeutic strategy in advanced stage disease remains controversial. Theoretically resectable, Stage IIIa disease includes a high proportion of non-resectable nodal diseases. Overall 5-year survival after surgery remains lower than 15%. Randomized trials comparing the results of surgery alone with induction chemotherapy followed by surgery showed a significant benefit to induction therapy. Currently, Stage IIIb diseases are considered unresectable; nevertheless, selected patients are able to undergo an extended resection after induction treatments. In highly selected cases, a surgical resection can be performed in T4 tumors. Surgical resection must be included in a combined multidisciplinary strategy of treatment, and is proposed only for responders. Resectability criteria have to be defined with clinical trials designed to increase the local control by surgery. Thus, so-called Stage IIIb tumors can be divided in two subcategories: potentially resectable and definitively non-resectable. Some locally advanced, initially unresectable tumors (Stage IIIb) can become operable after induction chemoradiotherapy. The French staging system, based upon prognostic and therapeutic subcategories, splits N2 involvement into two subcategories: mN2 (minimal), found at the thoracotomy; and cN2 (clinical), histologically proven at the pre-treatment staging. T4 tumors are divided in potentially resectable T4 1 (invasion of superior vena cava, carina, lower trachea, left atrium), and definitively non-resectable T4 2 (malignant pleural or pericardial effusion, invasion of oesophagus, and vertebrae). Thus, Stage III can be separated into three subcategories, A, B, and C, instead of the two current substages. Stage IIIA includes T3 N1 M0 and T1-T3mN2M0 tumors. Stage IIIB includes T1-T3cN2M0 and T4 1 N0-N2MO tumors. Stage IIIC includes T4 2 N0-N3M0 and T1-T4 1 N3M0 tumors. In this way, the therapeutic options in non-small-cell lung cancer (NSCLC) will be clarified with 1) a "primary surgery" subgroup, including Stages I, II, and IIIA, 2) an "induction treatment" subgroup, including Stage IIIB, and 3) a "non-surgical" subgroup, including Stages IIIC and IV.