The aim of this study was to evaluate gastrointestinal metastases from primary lung cancer confirmed by autopsy. We identified and examined patients with a diagnosis of primary lung cancer over 33 years. We also reviewed patients with gastrointestinal metastases including the stomach, small bowel, and large bowel. This study comprised 470 patients with lung cancer. We detected 56 (11.9%) cases with gastrointestinal metastases. There were 12 (30%) cases with gastrointestinal metastases among 40 cases with large cell carcinoma. The histological type of large cell carcinoma led to a significantly higher rate of gastrointestinal metastases compared with that of non-large cell carcinoma (P=0.004, odds ratio 3.524). Life threatening gastrointestinal metastases occurred in 12 cases and five occurred in large cell carcinoma. Gastrointestinal metastases from primary lung cancer may occur in the clinical course and result in life threatening gastrointestinal metastases, particularly if patients have the histological type of large cell carcinoma.