['The efficacy of routine second-look endoscopy (SLE) to detect or prevent bleeding after gastric endoscopic submucosal dissection (ESD) has not yet been validated.', 'The aim of this study was to determine whether SLE affects clinical outcomes including bleeding and morbidity after gastric ESD.', 'A prospective, randomized, controlled study with consecutive data analyzed on an as-treated basis.', 'A single, tertiary-care referral center.', 'A total of 182 patients.', 'Gastric ESD and SLE.', 'Incidence of and risk factors related to bleeding after ESD and outcomes by univariate or multivariate analysis.', 'Among 182 patients enrolled, 74 and 81 patients were assigned to the SLE and no-SLE groups, respectively. Two groups were observed closely for 4 weeks. Bleeding occurred after ESD in 21 patients (13.5%). Hemoglobin loss (≥2.0 g/dL) was observed in 20 patients, and melena developed in 1 patient after ESD. However, only 1 patient needed a transfusion. Twelve patients (16.2%) in the SLE group and 9 in the no-SLE group (11.1%) experienced bleeding after ESD. The frequency of bleeding after ESD was not significantly different between the 2 groups (P = .66). There were no risk factors related to bleeding after ESD.'] Is second-look endoscopy associated with better clinical outcomes after gastric endoscopic submucosal dissection : a prospective , randomized , clinical trial analyzed on an as-treated basis?