This is one case report of coexisting two histologically different carcinomas in the different lobes of the right lung, which operated the right pneumonectomy in the Dept. of Thoracic and Cardiovascular Surgery Hanyang University Hospital. The 43 years old male patient complained coughing, blood tinged sputum and weight loss. The chest films [PA and lateral view] showed a small round hazy shadow in the posterior segment of the right upper lobe and irregular hazy densities in the right middle lobe and hilar area. Histopathologically, the tumor in the posterior segment of the right upper lobe was consisted of a tissue of adenocarcinoma and the tumor in the right middle lobe was consisted of a tissue of well-differentiated bronchial squamous cell carcinoma.