BACKGROUND: Several techniques have been proposed for endoscopic mucosal resection (EMR) of large flat adenomas of the colon. AIMS: to evaluate bleeding and recurrence rates after EMR of large sessile colonic adenomas as a function of different techniques. METHODS: 65 sessile colonic adenomas larger than 2 cm were treated by EMR in 57 patients. Mean larger diameter of the polyps was 28 mm (20-80). Lesions were lifted with saline solution alone (n=26) or saline solution plus epinephrine 1:10.000 (n=39). En bloc EMR (n=29) or piecemeal EMR (n=36) were performed. APC was used when residual adenomatous tissue was recognized after EMR (n=36). Endoscopic follow-up was performed at 3, 6 and 12 months. RESULTS:. Procedural bleedings occurred in 9 EMR (13,8%): 5/26 in the saline group and 4/39 in the epinephrine group (p=ns). They were all successfully treated by APC and/or clips application. All the resected specimens were retrieved for histological examination: 22 were adenomas with LGD, 26 with HGD/in-situ carcinoma, 14 were carcinomas infiltrating the upper third of the submucosa, 3 were infiltrating deep submucosa. 13 patients (15 polyps) eventually underwent surgery: none of these patients had lymph node metastases or residual adenoma at the site of polypectomy; five patients (five polyps) were lost to follow-up. Residual adenomatous tissue or recurrences were observed at the site of 13 EMR: 8/21 in the APC group and 5/24 in the non APC group (p=ns), 5/20 in the en bloc and 8/25 in the piecemeal group (p=ns), respectively. All recurrences were endoscopically retreated (by APC or EMR) with complete eradication in 10 cases while in 3 patients treatment is still on-going. CONCLUSION: EMR for large colonic polyps is feasible and safe. Adrenaline injection did not significantly prevent bleeding; use of APC on residual adenoma and type of resection did not significantly influence the recurrence rate. Being incidence of recurrence usually high for these polyps, a close follow-up is required. Endoscopic retreatment of recurrences is able to obtain the complete eradication of the lesion.