Background: The risk of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) could be related to technical or patient-related factors. The aim of this study was to assess whether clinical variables and co-morbidities influence the risk of developing PEP. Methods: Data were retrieved from the Swedish GallRiks registry, including all ERCP procedures performed in 2006-2014 for common bile duct stones. A total of 15 800 procedures were identified and cross-checked. Univariable and multivariable logistic regression analyses were conducted with the endpoint of PEP using the following co-variables: age, sex, ASA grade, previous history of acute pancreatitis, diabetes, hyperlipidaemia, hypercalcaemia, kidney disease and liver cirrhosis. Results: Women (odds ratio (OR) 1.33, 95 per cent c. i. 1.14 to 1. 55), patients aged less than 65 years (OR 1. 68, 1. 45 to 1. 94), patients with hyperlipidaemia (OR 1. 32, 1. 02 to 1. 70) and those with a previous history of acute pancreatitis (OR 5. 44, 4. 68 to 6. 31) had a significantly increased risk of PEP. In a subgroup analysis of patients with a previous history of acute pancreatitis, the mean time from previous pancreatitis to ERCP 4423 days in patients who developed PEP vs 6990 days in patients who did not (P = 0. 037). However, when the previous episode of pancreatitis had occurred more than 30 days before ERCP, this association was no longer significant (P = 0. 858). Patients with diabetes had a decreased risk of PEP (OR 0. 64, 0. 48 to 0. 85). Conclusion: Age, sex, hyperlipidaemia and previous history of recent acute pancreatitis increase the risk of PEP. The reduced risk of PEP in patients with diabetes should be explored in future studies.