Endoscopic mucosal resection (EMR) is considered an effective endoscopic treatment of sessile polyps and non-polypoid colorectal neoplasia. A limitation of this technique is the risk of incomplete endoscopic resection, which can lead to local residual neoplasia development. Aim: Identification of the risk factors associated with local residual neoplasia (LRN) onset. Methods: Retrospective analysis was performed on colorectal neoplasia EMRs in one high-volume tertiary-referral endoscopic center in 2013-2015. Individuals with at least one follow-up colonoscopy after the initial EMR were included. LRN was defined as the histopathological presence of neoplastic tissue at the post-EMR site. Univariate and multivariate analysis of factors associated with LRN were performed.