Background and Aim: Endoscopic mucosal resection (EMR) with a cold snare is gaining increasing acceptance as an effective therapy for large laterally spreading lesions in the colon. The cold snare technique offers a favorable risk profile, with low rates of bleeding, perforation, and post-procedure pain compared to the more widely used hot snare EMR technique. While there is increasing acceptance of cold snare EMR for the removal of medium (10-19mm) and large (≥20mm) sessile serrated lesions (SSLs), concerns remain about its suitability for the removal of similar sized adenomas. We aimed to study the differences in safety and efficacy of cold snare EMR for SSLs as compared to adenomas at our institution. Methods: Data was collected retrospectively for EMR procedures of Paris IIa SSLs and adenomas performed at a single centre between 01/02/2018 and 31/05/2020. The Provation endoscopy reporting program was used to source size, morphology, method of resection, and recurrence data. Complications were captured through a review of medical records that included a one-month follow-up phone call. Results: A total of one hundred forty-two eligible EMR procedures were performed over the study period (Table 1). The SSLs and adenomas were similarly located throughout the colon. One hundred nineteen patients had completed their six-month surveillance colonoscopy (SC1) and forty-six their eighteen-month surveillance (SC2). The overall recurrence rate at SC1 was considerably lower in the SSL group (3.2% vs 14.0%, OR 0.20, P 0.05). The difference was most appreciable in lesions 20mm or larger (3.1% vs 18.4%, OR 0.14, P 0.08). Recurrence was able to be treated endoscopically in all cases. There were no complications reported in either group. Conclusion: Our study demonstrates both safety and efficacy of the cold snare technique for medium and large SSLs, while raising concerns about efficacy, but not safety, for similarly sized adenomas. It is reassuring that recurrence was able to be treated endoscopically in all cases. Considering this and the impressive safety profile of the cold EMR technique, particularly in high risk patients, it may still have a place in the EMR of medium and large adenomas. Further research is required to understand the reasons for this increased recurrence and to determine the optimal technique for cold snare EMR of adenomas.