Introduction: Difficult cannulation in cases of endoscopic retrograde cholangiopancreatography (ERCP) could be associated with several factors, including: type of major papilla, however, there are limited data regarding this possible association. Objectives: To determine the association between the type of papilla and difficult biliary cannulation. Materials and methods: A retrospective cross-sectional analytical study was conducted in patients over 18 years old who underwent ERCP on papilla naive, from July 2019 to April 2021, in a private institution. Unsuccessful cannulations were excluded. The papilla was classified based on Haraldsson classification. The crude association and adjusted for possible confounders between the type of papilla and difficult cannulation was evaluated. Relative risks (RR) and 95% confidence intervals were calculated. Results: 188 patients were include...