Impaction of a stone at the duodenal papilla can obstruct biliopancreatic outflow and thereby lead to acute pancreatitis. But not all patients with an impacted papillary stone (IPS) had the clinical features of pancreatitis. This study aimed to identify factors associated with acute pancreatitis in patients with IPS.We retrospectively analyzed patients with IPS who underwent endoscopic retrograde cholangiopancreatography (ERCP) at Tianjin Nankai Hospital. Clinical factors were compared between patients with/without acute pancreatitis before ERCP. Factors associated with acute pancreatitis were identified by univariable and multivariable binary logistic regression.The final analysis included 174 patients with acute pancreatitis (pancreatitis group, PG) and 130 patients without acute pancreatitis (non-pancreatitis group, NPG). Preoperative incidences of jaundice (85.6 vs. 72.3%), acute cholangitis (54.6 vs. 33.8%), and hyperlipidemia (39.1 vs. 22.3%) were higher in the PG than in the NPG (Jaundice, acute cholangitis, and hyperlipidemia are independent risk factors for acute pancreatitis in patients with IPS. Prompt ERCP in patients with these features might reduce acute pancreatitis risk. Dot/circular papillary orifice may be an anatomical factor of acute pancreatitis, which needs more evidence.