Abstract: Objective To investigate the effects of long-term use of aspirin or clopidogrel on the bleeding incidence after endoscopic biopsy. MethodsClinical data were collected from 450 patients who underwent endoscopic biopsy in our hospital from July 2011 to December 2014 before retrospective analysis. All the cases were randomly divided into an observation group treated with aspirin or clopidogrel and a control group treated without aspirin or clopidogrel (n=225). Both groups were compared for related bleeding risk indicators. ResultsThere were no significant differences in bleeding time between the two groups (P>0.05). After endoscopic biopsy, the level of hemoglobin was remarkably lower in the observation group than its preoperative level (P<0.05). The related factors of hemoglobin changes included more than three biopsy samples taken, age≥70 years old and no preventive treatment with proton pump inhibitors. ConclusionLong-term use of aspirin or clopidogrel may not increase the incidence of bleeding after endoscopic biopsy.