Authors compared the preoperative CT staging of lung cancer with postoperative staging on the base of pathologic diagnosis. We reviewed series of 35 patients with lung cancer who underwent CT and surgery to evaluate accurate staging. CT predicted the stage of lung cancer accurately in 23 patients out of 35. 10 cases were over-staged and two cases were under-staged by CT. Most frequent site of the misinterpretation in CT staging was the subcarinal lymph node. Another frequent sites were mediastinal and chest wall invasion.