Recommendations for classifying regional lymph node stations for lung cancer staging have been adopted by the American Joint Committee on Cancer (AJCC) and the Union Internationale Contre le Cancer. The objective was to unify the two systems that have been in common use for the past 10 years; that is, the schema advocated by the AJCC, adapted from the work of Tsuguo Naruke, and the schema advocated by the American Thoracic Society and the North American Lung Cancer Study Group. Anatomic landmarks for 14 hilar, intrapulmonary, and mediastinal lymph node stations are designated. This classification provides for consistent, reproducible, lymph node mapping that is compatible with the international staging system for lung cancer. It is applicable for clinical and surgical-pathologic staging.