Among various types of cancers, pancreatic cancer is known to be prone to venous thromboembolism (VTE). We investigated the complication rate of VTE and risk factors for deep vein thrombosis (DVT) in patients with pancreatic cancer undergoing chemotherapy. We retrospectively analyzed the data of 51 patients with pancreatic cancer who had undergone chemotherapy at our hospital from January 2016 to March 2021, had their D-dimer levels measured at the initial visit, and had undergone venous ultrasonography if D-dimer levels were elevated. At the initial visit, the complication rate of VTE was 35.3% (18/51 patients). Multivariate analysis revealed that the risk factors for DVT were primary tumors in the pancreas's body and tail and elevated D-dimer levels. Patients with DVT tended to have shorter overall survival than those without (218 vs 523 days). Patients with pancreatic cancer frequently develop VTE and should be aggressively screened for thrombosis, particularly in those with primary tumors in the pancreas's body and tail and elevated D-dimer levels.