Acute pancreatitis (Ap) is a common adverse event (Ae) of endoscopic papillectomy (ep). prophylactic plastic pancreatic stent (ppS) placement appears to prevent Ap. We evaluated factors associated with post-ep Ap by a retrospective analysis of patients with tumors of the duodenal papilla who underwent EP from January 2008 to November 2016 at 2 tertiary care centers. Clinical, laboratory, endoscopic ultrasound parameters, and ppS placement were evaluated. Seventy-two patients underwent ep (37 men), with mean age of 60.3 (31-88) years. Mean main pancreatic duct (MPD) diameter was 0.44 (0.18-1.8) cm. Mean tumor size was 1.8 (0.5-9.6) cm. Tumors were staged as uT1N0, uT2N0, and uT1N1 in 87.5%, 11.1%, and 1.4%. Thirty-eight AEs occurred in 33 (45.8%) patients, with no mortality. Total bilirubin, tumor size, MPD diameter, and PPS placement had odds ratios (ORs) of 0.82, 0.14, 0.00, and 6.43 for AP. Multivariate analysis (PPS placement × MPD diameter) showed ORs of 4.62 (95%CI, 1.03-21.32; p = 0.049) and 0.000 (95%CI, 0.00-0.74; p = 0.042) for AP. In conclusion, patients with jaundice, large tumors, and dilated MPD seem less likely to have post-EP AP. PPS placement was associated with a higher risk of Ap, which may question its use.