Calcifying fibrous tumors (CFTs) are unusual benign tumors of childhood, located primarily in soft tissues, pleura, and peritoneum. The cause and pathogenesis are unclear. We report a rare case of a CFT in a 2-year-old boy who presented with vomiting and abdominal distension. An abdominal X-ray showed an elliptical, calcific shadow in the LUQ area mimicking a foreign body. An internally protruding mass along the lesser curvature of the gastric body was an incidental finding during upper endoscopy, biopsies of which were negative. Abdominal CT showed a 4.5×3.2 cm soft tissue mass of the gastric wall with calcifications. A diagnosis of gastric submucosal mass was suspected and a wedge resection of the stomach was performed. On microscopic examination, the tumor was composed of whorls of dense hyalinized collagen bundles with a few fibroblasts. There were also amorphous dystrophic calcifications and nodular aggregates of mononuclear inflammatory cells. Immunohistochemically, spindle cells did not stain for anaplastic lymphoma kinase-1 (ALK-1), CK, smooth muscle actin (SMA), or desmin. Taken together, the mass was compatible with a CFT of the gastric wall. This is the first reported case of CFT in a Korean child.