Endoscopic submucosal dissection (ESD) for colorectal neoplasms is not widely performed because of the high risk of perforation. Perforations are divided into macroperforations and microperforations. Currently, there is a limited amount of clinical data on the outcome of patients with these types of perforations during colonic ESD. The aim of this study was to investigate the clinical outcome of patients who sustained colon perforations during ESD. We also compared the clinical outcome of patients with microperforations and those with macroperforations. This study enrolled 101 patients with colorectal laterally spreading tumors (LST) who underwent ESD. We retrospectively reviewed their medical records, including patient demographic data and the clinical, endoscopic, and pathologic features. In the cases where perforation had occurred, the course of hospital treatment was analyzed. All ESD-related perforations were divided into macroperforations and microperforations. A macroperforation was defined as a gross perforation that occurred during an ESD procedure and a microperforation was defined by free air visible on X-rays after the procedure. Of the 101 enrolled patients, 9 (8.9 %) developed perforations. The most common tumor morphology was nongranular-type LST (5 of 9 cases, 55.6 %) based on endoscopic examination. Five patients had microperforations and four had macroperforations. All macroperforations were closed primarily by endoclips during ESD. The endoscopic characteristics did not differ between the groups. However, the length of hospital stay and the mean duration of NPO and antibiotic treatments were longer for microperforation patients. All patients had conservative nonsurgical management such as fasting, intravenous antibiotics, and nasogastric tube drainage. The clinical complications for microperforation patients were worse than those for macroperforation patients. However, the clinical prognoses of patients with perforations that occur during colonic ESD are favorable.