Gastric Hodgkin's lymphoma is extremely rare. We present a case of primary Hodgkin's lymphoma arising in the stomach of a 65-year-old woman. The patient complained of epigastric discomfort and reflux for one month. Endoscopic examination revealed a protruding lesion characterized by a smooth surface at the antrum. An abdominal computed tomography uncovered a 2.5 x 2.0 cm, exophytic submucosal mass. After the tentative preoperative diagnosis of a gastrointestinal stromal tumor, a gastric wedge resection was performed. Microscopic examination of the mass demonstrated a diffuse proliferation of large atypical lymphoid cells with mono- and binucleated pleomorphic nuclei and prominent nucleoli. Immunohistochemically, the tumor cells were positive for CD30, CD20, and CD79a, whereas they were negative for cytokeratin, carcinoembryonic antigen, CD3, CD15, epithelial membrane antigen, and anaplastic lymphoma kinase-1. Based on the morphological features and immunohistochemical results, in addition to the clinical findings, a diagnosis of primary gastric Hodgkin's lymphoma was established.