Background and purpose: Venous thromboembolism (VTE) is a potentially fatal perioperative complication. Understanding the risk factors for deep vein thrombosis (DVT) and initiating appropriate prophylaxis is pivotal for reducing the risk of VTE. The purpose of this study was to clarify the perioperative risk factors for DVT in patients undergoing surgery for gastric cancer. Methods: We reviewed the findings of lower limb ultrasonography performed in 160 patients who underwent gastrectomy for gastric cancer. Results: The preoperative and postoperative incidence of DVT was 4.4% (7/160) and 7.2% (11/153), respectively. All postoperative DVTs were of the distal type, whereas preoperative DVTs were of the proximal (n = 3) and distal type (n = 4). None of the patients suffered symptomatic VTE. Multivariate analysis indicated that depth of invasion and D-dimer concentration were independent risk factors for preoperative DVT and that gender and performance status were risk factors for postoperative DVT. Receiver operating characteristic analysis revealed that the optimal cut-off D-dimer concentration was 1.4 μg/mL. Conclusions: The incidence of perioperative DVT was low for patients undergoing gastric cancer surgery. Therefore, the risk-stratified application of perioperative pharmacologic thromboprophylaxis is thought to be more appropriate than routine pharmacologic thromboprophylaxis for Japanese patients undergoing surgery for gastric cancer.