We report a case of a 5-aminosalicylate-induced pancreatitis in a patient with Crohn's disease. These findings suggest that some side effects, traditionally thought to be related to sulphafapyridine, are really due to 5-aminosalicylate. The good prognosis of this rare complication depends on the early withdrawal of the drug. Therefore the degree of the clinical suspicion plays a essential role in the appropriate diagnosis, but a challenge with mesalazine must be carried out in those patients in which other causes of pancreatitis could not be excluded.