IntroductionDelayed gastric emptying (DGE) is one of the most troublesome complications of pancreaticoduodenectomy (PD). Diabetes mellitus (DM) is one of the risk factors for pancreatic cancer. Moreover, several studies have shown that diabetic patients tend to have a high incidence of upper gastrointestinal symptoms such as nausea, vomiting and DGE. Here, we compared the influence of DM on the incidence of DGE after PD. MethodsWe retrospectively analysed 67 cases of PD with pancreaticogastrostomy. These patients were categorized into the following two groups: the DM group included patients with DM, and the NDM group included patients without DM. The incidence of DGE was determined and compared between the two groups. ResultsIn the DM group, 76.5%, 5.9% and 17.6% of the subjects developed classes A, B and C DGE, respectively; the corresponding values in the NDM group were 58%, 22%, and 20%. The incidence of DGE did not differ between the two groups (P < 0.2771). ConclusionsDM does not accelerate DGE in patients who have undergone PD. Preoperative DM does not appear to play a key role in post-operative DGE after PD.