We considered 33 patients to have a multiple primary lung cancer (MPLC) at our hospital from January 1986 to August 2001. We used the criteria of Martini and Melamed for MPLC. Sixteen patients developed metachronous cancer within 0.8 to 9.4 years of the first operation (mean 4.2 years), while 17 patients had synchronous cancers. The most common histologic pair was squamous cell carcinoma-squamous cell carcinoma (45%). The next was adenocarcinoma-adenocarcinoma (21%). Stage I lesions occupied 80% of all lesions. Nine patients underwent lobectomy, while 9 patients underwent surgery including a limited operation. Eleven patients had non-surgical local treatment including photodynamic therapy (PDT), brachytherapy, and radiation therapy. Five-year survival for patients with synchronous and metachronous disease from second operation was 36.1% and 40.1%, respectively. Survival of patients including only stage I non-small cell lung cancer (NSCLC) lesions was significantly better compared with those including stage II or III NSCLC and SCLC lesions (p = 0.002). Therefore it is very important to perform close follow-up surveillance for early detection of cancer.