From 1974 to 1988, we experienced 36 benign tumors or tumor-like lesions of the lung out of 721 thoracotomies performed for the treatment of lung tumors. There were 21 hamartomas, nine inflammatory pseudotumors and six sclerosing hemangiomas. On average patients were in their fifth or sixth decade, which was somewhat younger than that for bronchogenic carcinoma. Marked female predominance was noted in the cases of sclerosing hemangioma. There were no particular characteristics with respect to symptoms or location of the tumors. Over 80% of the benign tumors were less than 30 mm in diameter. Diagnosis of the benign tumors was usually not difficult from the routine chest X-ray film. However, some cases produced shadows on X-ray films closely resembling those of lung cancer. Surgical removal preserving as much lung parenchyma as possible is indicated for definite diagnosis and treatment.