In order to expand the availability of endoscopic submucosal dissection (ESD), measures to facilitate the procedure are necessary. When bleeding occurs, the examiner's field of vision is critically impaired, and ESD becomes less efficient and more hazardous because of the presence of submucosal hematoma and covered blood clot. We propose the use of polyethylene glycol (PEG) irrigation as a simple and effective measure to improve visibility during submucosal dissection, particularly when bleeding occurs. PEG irrigation facilitates further dissection by allowing a better recognition of the submucosal fibers and muscularis propria layer.