This study aimed to clarify the significance of splenectomy (Sp) for upper gastric carcinoma with invasion to the greater curvature. The Japan Clinical Oncology Group (JCOG) conducted a phase III randomized clinical trial (JCOG 0110), where the significance of Sp in total gastrectomy (TG) for upper gastric carcinoma without invasion to the greater curvature was not proved because Sp did not contribute to an improved prognosis. From 1992 to 2010, 167 patients underwent TG for carcinoma of the upper stomach, except for patients with carcinoma of the residual stomach. Among them, 60 patients with tumor invasion to the greater curvature of the upper stomach (Gre group) were enrolled. Within the Gre group, the following factors were compared between the Sp group (n = 30) and non-Sp group (n = 30): patient background, postoperative staging, rate of neoadjuvant chemotherapy, surgical outcomes and rates of R0 resection, morbidity, adjuvant chemotherapy, and overall survival (OS). The Gre group patients were relatively younger, and tumor size and the numbers of Borrmann type 4 tumors, circumferential lesions, undifferentiated type lesions, and advanced cases were significantly larger than those in the non-Gre group. There were also significant differences in patient age and organs resected other than the spleen between the Sp group and non-Sp group. There was no significant difference in OS between the 2 groups. The significance of Sp for upper gastric carcinoma with invasion to the greater curvature was equivocal because the patients received no survival benefit by undergoing Sp.