Objectives: The best treatment for patients with Behçet's disease (BD) with major vessel thrombosis has not been fully determined. Our objective was to raise this therapeutic dilemma and to call for controlled studies to help establish guidelines to address this problem. Methods: Three patients with BD and major vessel thrombosis whom we recently encountered are described. Their cases were presented to rheumatologists from Turkey, Israel and the USA. The physicians were asked about the kind of treatment they would give each patient at diagnosis of thrombosis and if they chose to give anticoagulation and for long. Results: Fifty-five Turkish, 33 Israeli and 25 American rheumatologists responded to the questionnaire. More than 87% of the Israeli and American rheumatologists would give anticoagulation at the time of diagnosis for the cases of venous thrombosis compared with only 40-44% of the Turkish physicians. In these cases 56% of the American and 45% of the Israeli rheumatologists would give warfarin for life compared with only 5-18% of the Turkish physicians. Regarding a case with intra-cardiac thrombus, 96% of American, 94% of Israeli, and 60% of Turkish rheumatologists would start anticoagulation at diagnosis while 70%, 39% and 33%, respectively would give this treatment for life. Conclusion: The therapeutic approach towards thrombosis in Behçet's disease differs significantly among rheumatologists from different countries. The different prevalence of the disease in these countries may explain this difference. A randomised controlled prospective trial is needed in order to determine the exact role of anticoagulant treatment in BD. © Copyright CLINICAL AND EXPERIMENTAL RHEUMATOLOGY 2012.