Despite the growing understanding of the pathophysiological processes in the perioperative period and significant advancements in surgical techniques, operative treatment for gastric cancer remains a challenge for surgeons, especially because the primary procedure of total or nearly total gastrectomy must at times be extended by the resection of other organs. The aim of the study was to asses the influence of concomitant splenectomy in patients undergoing curative surgery for gastric cancer on postoperative complications. The study population consisted of 258 patients who underwent surgical treatment for gastric cancer with the intention to treat. The study assessed the influence of extending the surgical intervention by splenectomy on postoperative complications, both general and surgical, including the most severe of these, i.e. oesophago-gastric anastomotic leakage, duodenal stump leakage and peritoneal fluid infections. Among the 258 gastric cancer patients receiving curative surgical treatment, the most common simultaneous intervention was splenectomy: 42/258 (16.3%), which was also accompanied by partial pancreatectomy in 8 cases. The number of surgical postoperative complications, major and minor, was similar in both subgroups: with and without splenectomy. Minor general complications, such as pyrexia with no clinically apparent reason, atelectasis, pneumonia and pleural effusion were statistically significantly more common in the subgroup with splenectomy (p=0.0001). Splenectomy performed concomitantly with gastrectomy for gastric cancer increases the risk of minor general complications. However, it does not increase the risk of severe surgical complications, such as oesophago-intestinal anastomotic leakage and does not increase the risk of death.