Introduction: In 1987 Frey and Smith described their operation for chronic pancreatitis which involved an extended lateral pancreaticojejunostomy combined with removal by coring of the parenchyma in the anterior aspect of the head of the gland. The Frey pancreaticojejunostomy has now been reported from centres across the world. However, unlike more clearly defined procedures such as pancreatoduodenectomy, there is no standardization of the Frey operation resulting in potential heterogeneity. This study is an overview of the current world experience of the Frey operation with emphasis on variance in reporting. Methods: A search of the literature was performed using the Scopus database for publications between 1st January 1970 and January 2018. The keyword and MESH heading “chronic pancreatitis”, was used together with the term “Frey Pancreaticojejunostomy”. The risk of bias was assessed using the Cochrane collaboration’s tool for assessing risk of bias in non-randomized studies of interventions. The protocol was reviewed by the research and development department of Central Manchester University Hospitals NHS Foundation Trust. There were 34 reports of the Frey pancreaticojejunostomy and these constitute the study population Results: Data are affected by selection bias and reporting bias. In terms of assessing the morphology of the gland being operated, maximum antero-posterior diameter of the main pancreatic duct was reported in 19 (56%) of reports, antero-posterior diameter of pancreatic head in 13 (38%). Portal vein patency was confirmed in 4 (12%). The presence or absence of a concomitant biliary stricture was reported in 22 (65%) and a duodenal stricture in 14 (41%). Conclusion: The Results demonstrate that there is substantial variation between centres in reporting of the Frey operation. This variance compromises the value of comparative outcomes of this procedure and highlights the need for better standardization of the reporting of outcomes of surgery for chronic pancreatitis.