The simultaneous occurrence of a gastrointestinal stromal tumor (GIST) and a gastric adenocarcinoma is uncommon, and has rarely been reported in the literature. The present report describes the case of a 74-year-old male patient who initially presented with an adenocarcinoma that had invaded the antral mucosa. Computed tomography then revealed the presence of a suspected GIST, in the form of a $2{ imes}2$ cm mass at the hilum of the spleen. In view of the advanced age of the patient, a surgical approach that would minimize risk and maximize quality of life was preferred. The patient therefore underwent simultaneous laparoscopy-assisted distal gastrectomy for the adenocarcinoma and wedge resection for the GIST. This approach was only chosen after confirming that it would be possible to preserve three or more of the short gastric arteries that supply the area below the wedge resection site. This may be considered a feasible apapproach to the management of the simultaneous occurrence of a mid-to-low gastric body adenocarcinoma and a high gastric body GIST.