Background <p>Identifying the underlying cause of acute pancreatitis is fundamental for prevention of recurrence. However, no standardised algorithm for determining its aetiology exists.</p> Aims <p>This survey study aimed to investigate the international variations in diagnosis, workup protocols and follow-up of acute pancreatitis.</p> Methods <p>A 37-item international questionnaire was developed by a multidisciplinary team within the Pancreas 2000 program. The survey was distributed through social media platforms, e-mails and conference presentations. Responses were collected anonymously.</p> Results <p>The survey received 247 responses from 36 countries, with 96% of respondents based in Europe; there were 56% gastroenterologists (N = 138), 34% surgeons (N = 84).</p> <p>Endoscopic ultrasound and magnetic resonance cholangiopancreatography were equally chosen as the preferred initial diagnostic test (34%, N = 85 each) in cases of acute pancreatitis without identified aetiology after the standard workup. Compared to surgeons, gastroenterologists used endoscopic ultrasound more (5% vs. 29%, p &lt; 0.001) and favoured it as the ideal initial diagnostic tool for determining the aetiology (17% vs. 41%, p &lt; 0.001).</p> <p>Most respondents (79%, N = 194) didn’t recommend cholecystectomy when there was no evidence of biliary aetiology.</p> <p>The majority (89%, N = 220) recommended follow-up for moderate and severe acute pancreatitis with an unknown aetiology after initial admission; 17% (N = 42) did not recommend any follow-up.</p> Conclusions <p>This survey reveals significant disparities in the methods used to determine the aetiology of acute pancreatitis across different regions and centres within Europe. We share a common understanding that identifying the acute pancreatitis aetiology is critical to prevent recurrence. However, the absence of a validated protocol for this process is a notable gap in the clinical practice.</p>