Purpose: Anomalous pancreaticobiliary junction (APBJ) is a rare union of the biliary and pancreatic ducts (PD), which is associated with pancreaticobiliary malignancy (PBM). We characterize our experience with this condition in a Western population. Methods: We retrospectively reviewed an ERCP database of 7467 pts at Maine Medical Center from January 1991-February 2011. Clinical, surgical and pathological data was reviewed. Results: APBJ was found in 26 pts (F:18, M:8, median age 48 yrs, range 4-71 yrs, 23 Caucasians, 1 African-American, 1 Hispanic, 1 Asian, 0.35% incidence in ERCP over 20 yrs). 7 pts had type I union, 17 pts had type II union. Type I choledochal cyst (CC) was present in 19 pts. 22 pts presented with abdominal pain, 5 with jaundice, 14 with acute pancreatitis (AP), and 3 with chronic pancreatitis (CP). The average time of onset of symptoms to diagnosis (dx) was 15.8 mos (range 0-78 mos). Pancreas divisum was found in 4/26 pts (complete n = 2, incomplete n = 2). Sphincterotomy (ES) was performed in 22 pts. CBD stones were extracted from 5 pts. Of pts presenting with pancreatitis, ES was performed in 14/14 with resolution of AP in 100%. Of 5 pts with recurrent AP, 2 resulted from proteinaceous debris in remnant CC stumps, 1 had pancreas divisum, 1 had chronic pancreatitis with PD stricture, and 1 had not undergone prior ES. PBM was present in 5 pts (gallbladder cancer n = 1, stage I; cholangiocarcinoma (CCa) n = 4, 3 stage IV, 1 stage II). Of the 4 pts with CCa, 2 pts who had prior biliary surgery during childhood presented with stage IV disease (1 with choledochoduodenostomy and partial CC resection 59 yrs prior to dx, 1 with cholecystojejunostomy without CC resection 48 yrs prior). 2/5 pts with jaundice presented with PBM. 17 pts underwent cholecystectomy. Of the 19 pts with type I CC, 14 pts underwent CC resection (10/14 with complete resection through the pancreatic head). 7/10 pts with complete CC resection had preoperative PD stent placed which assisted with CC dissection through the pancreatic head. Excluding the pts with biliary surgery during childhood, no surgical patients developed PBM (average follow up 3.8 yrs, range 0-16.6 yrs). Conclusion: APBJ is rare in a Western population. Definitive therapy for recurrent AP involves ES, and potentially full CC resection. Avoidance of PBM necessitates resection of biliary mucosa, including gallbladder and choledochus. Preoperative PD stenting appears to assist with complete CC resection.