Abstract: Objective To analyze the safety of endoscopic submucosal dissection (ESD) in the treatment of colorectal laterally spreading tumors with diameters >3 cm in the elderly. Methods The clinical data of patients with colorectal laterally spreading tumors 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(cm), pathological type, procedural time (m), hospitalization time(d), en bloc resection rate, en bloc RO resection rate and complications were c ompared between the two groups. Results There were no significant differences in gender, lesion location, lesion type, lesion size, pathological type , average procedural time , hospitalization time , en bloc RO resection rate and en bloc resection rate between the two groups. The average procedural time was 52.1±12.0m and 50.8±12.2m,and the hospitalization time was 7.6±1.5d and 7.4±1.5d, 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 colorectal laterally spreading tumors with diameters >3 cm in the elderly.