Background: While thiopurines are considered safe in humans, they are still pregnancy FDA category D drugs. Prevention of postoperative recurrence is a challenge in clinical practice in Crohn's disease. The ECCO consensus states that thiopurines should be considered in high-risk patients. Aim: To perform a worldwide survey for evaluating the extent to which gastroenterologists who are experts in the field of IBD are utilizing thiopurines during pregnancy and in the postoperative setting in Crohn's disease. Methods: This was a Web-based Cross-sectional, statement-based survey, which was conducted among experts who have published at least once in the field of thiopurines in IBD. Results: Between December 20, 2009 and April 9, 2010, 175 questionnaires were received. The median number of IBD patients per physician per year was 400 (IQR 25-75th, 188-600) and the total number of IBD patients followed by all responders was 82,379. In a pregnant woman with a history of severe Crohn's disease in clinical remission after 1 year on azathioprine, 88.6% of experts usually continue azathioprine until delivery and 9.1% of physicians never administrate azathioprine during pregnancy. After ileocecal resection for Crohn's disease, 39.4% of physicians initiate azathioprine only in high-risk patients, 28% of practitioners prescribe azathioprine according to endoscopic evaluation, 20% of gastroenterologists systematically initiate azathioprine, and 12.6% have a different attitude. Conclusions: Almost 9 out of 10 physicians continue azathioprine throughout pregnancy. About 7 out of 10 physicians prescribe azathioprine in the postoperative setting according to ECCO recommendations, whereas one-fifth of practitioners systematically initiate azathioprine after surgery.