Purpose: This study was performed to evaluate the usefulness of computed tomography (CT) gastrography in the surgical management of a gastric gastrointestinal stromal tumor (GIST). Materials and Methods: We retrospectively analyzed the clinicopathologic data of 38 patients who had undergone CT gastrography from among patients who had gastric GISTS surgically resected at the Department of Surgery, Seoul National University Hospital, between January 2001 and February 2006. We compared CT gastrography data, including tumor size and location and distance from the gastroesophageal junction or pylorus with endoscopic, surgical and pathologic findings. Results: The longitudinal tumor locations on CT gastrography and endoscopy were identical to the surgical findings. For tumor sizes on CT gastrography of less than 5 cm, we performed 11 (42.3%) laparoscopic wedge resections from among 26 cases. In the 12 cases with tumor sizes of 5 cm or over, only 1 (8.3%) laparoscopic wedge resection was performed. When the tumor was located in the middle third of the stomach, a laparoscopic wedge resection was performed in 88.9% (8/9) of the cases, but when it was located in the upper or lower third, a laparoscopic wedge resection was performed in only 13.8% (4/29) of the cases. Conclusion: Three-dimensional information from CT gastrography allows the surgeon to perform preoperative planning, including accurate localization.