Abstract: Objective To analyze the safety of endoscopic submucosal dissection (ESD) in the treatment of laterally spreading tumors of the colorectum with diameters >3 cm in the elderly. Methods The clinical data of patients with laterally spreading tumors of the colorectum with a diameter of >3 cm performed ESD from January 2015 to December 2018 were collected and divided into 35 elderly patients (≥60 years old) and 30 non-elderly patients (<60 years old). The lesion location, lesion type, lesion size, pathological type, procedural time,length of stay, en bloc resection rate, en bloc RO resection rate and complications were compared between the two groups. Results There were no significant differences in gender, lesion location, lesion type, lesion size, pathological type , average procedural time , length of stay, en bloc RO resection rate and en bloc resection rate between the two groups. The average procedural time was (52.1±12.0) min and (50.8±12.2) min, and the length of stay was (7.6±1.5) d and (7.4±1.5) d, respectively. The en bloc RO resection rate was 88.6% and 90.0%, and the en bloc resection rate was 94.3% and 93.3%, respectively. There was no statistical difference in the incidence of perforation, bleeding, recurrence and stricture between the two groups. Conclusions ESD is a safe and effective method for the treatment of laterally spreading tumors of the colorectum with diameters >3 cm in the elderly.