F-18 2-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) is useful for surveys to detect bone metastasis because of its greater specificity than bone scintigraphy. However, FDG-PET is also known to yield false-positive results in acute fractures and inflammatory lesions, and distinguishing between benign and malignant lesions is difficult, even when semiquantitative methods are used. We report a case of multiple bone metastases of gastric cancer. One of the bone lesions that was positive for FDG uptake was benign, suggesting that FDG-PET can yield false-positive results.