T4 lung cancers are a heterogeneous group of locally advanced lung cancers. Treatment is palliative for the majority of patients, ranging from supportive care to chemoradiotherapy. In certain patients, however, surgery is beneficial and may be curative. Patients with T4N0M0 cancers invading the distal trachea, carina, left atrium, aorta, superior vena cava, or vertebral bodies may be surgical candidates. Radical resections of these T4 lung cancers have potential for cure if no mediastinal lymph node metastases (N2 or N3) occur and if resection is complete. Increased postoperative mortality exists and extends beyond 30 days, as evidenced by a 30-day mortality of 8% and a 90-day mortality of 18%. Improved palliation (median survival of 19 months) and cure (31% five-year survival) are possible in patients who meet the criteria, who undergo radical resection, and who are followed by physicians in facilities with special interests in extended resections. The use of induction therapy and surgery in T4 patients may further increase survival and the number of T4 patients in whom radical resection is possible. Radical resections are contraindicated in patients with T4 lung cancers associated with malignant pleural effusions. Unfortunately, these patients have the worst prognosis. If surgical palliation is an option, only pulmonary resection with pleurectomy and not pleuropneumonectomy should be considered. In contrast, lung cancers with the best prognosis are those T4 tumors diagnosed because of a satellite tumor nodule within the same lobe. Because radical resections are usually not required, operative mortality is not increased. Five-year survival in patients with satellite intralobar tumor nodules without mediastinal nodal metastases is comparable to survival of highly selected T4N0M0 patients who undergo radical resection. These two extremes of T4 lung cancers, malignant pleural effusion and satellite intralobar tumor nodules, generally are not considered for or do not require radical resections. It is debatable that the definition of T4 should include these entities.