A 73-year-old man presented with fatigue and weight loss. He had CT-proven splenic mass with fistulous connection to the greater curvature of the stomach, which suggested abscess. FDG PET/CT confirmed gastrosplenic fistula in addition to active lymph nodes in the gastrohepatic ligament and epigastric region. Pathological examination after the biopsy of the spleen was consistent with diffuse large B-cell lymphoma. Chemotherapy was administered with close clinical follow-up and resulted in the resolution of fistula without requirement for surgery.