Metastasis from squamous cell carcinoma of the lung to the stomach is extremely rare. 18F-FDG PET/CT demonstrated intense 18F-FDG uptake in the lower lobe of the left lung, stomach, and mediastinal lymph node in a 61-year-old man. Lower lobe of the left lung resection, mediastinal lymphadenectomy, partial gastrectomy, and esophagogastric anastomosis was performed. Immunohistochemical studies revealed squamous cell lung carcinoma in the left lung and metastatic carcinoma of gastric and lymph nodes. The present case further demonstrated the value of 18F-FDG PET/CT in the staging of malignant disease.