Endoscopic submucosal dissection (ESD) has been reported to be associated with a higher complication rate than standard endoscopic mucosal resection. We aimed to clarify the risk factors for delayed bleeding after ESD for early gastric cancer (EGC). 1083 EGCs in 968 consecutive patients undergoing ESD during a 4-year period were reviewed. Post-ESD coagulation (PEC) preventive therapy of visible vessels in the resection area, using a coagulation forceps, was introduced and mostly performed during the later 2 years. Various factors related to patients, tumors, and treatment including PEC were investigated using univariate and multivariate analysis with regard to delayed post-ESD bleeding, evidenced by hematemesis or melena, that required endoscopic treatment. Delayed bleeding occurred after ESD of 63 lesions (5.8 % of all lesions and 6.5 % of patients), controlled in all cases by endoscopic hemostasis; blood transfusion was required in only one case. Tumor location in the upper third of the stomach and PEC were independent factors indicating a lower rate of delayed bleeding according to both univariate and multivariate analysis. This retrospective study suggested that preventive coagulation of visible vessels in the resection area after ESD may lead to a lower bleeding rate.