Thirty patients have undergone multiple resections for non-small cell lung cancer from 1973 to July 1994, constituting 2.6% of 1,153 who had undergone pulmonary resection for such tumor. In the 22 patients for recurrent cancer, 15 resections of the ipsilateral lung and 9 of the contralateral lung were performed with no operative death. The survival rate following second resection in 22 patients was 33.8% at 3 years and 13.5% at 5 years. Survival rate was poor in patients with DNA aneuploid primary tumor and there was not a patients of 5 years survival. Three out of the 5 patients which had a diploid pattern in the primary tumor, showed an aneuploid pattern in the recurrent tumor. Long survival patients were founded only in the patients which had a diploid primary tumor. In the 8 patients for second primary lung cancer, 4 resections of the ipsilateral lung and 4 of the contralateral lung were performed, including two bronchoplastic surgery for early hilar squamous cell carcinoma. The survival rate following second resection in 8 patients was 64.2% at 5 years with good result. We concluded that an aggressive surgical approach is safe and warranted in patients with second primary lung cancer.