Endomyocardial fibrosis is very rare in Behcet's disease. The authors report the case of a 28 year old patient with Behcet's disease complicated by a pseudo-tumoral right ventricular formation on echocardiography. This misleading appearance suggested the diagnosis of cardiac thrombus or tumour and led to a surgical approach which revealed a fibrous moderator band suggesting endomyocardial fibrosis, confirmed by antomopathological analysis. Besides the originality of this case and the unusual pseudo-tumoral presentation, the authors underline the difficulties of establishing the diagnosis, despite the advances of medical imaging. The pseudo-tumoral intra-cardiac lesion in a suggestive clinical context (Behcet's disease) should raise suspicion of the diagnosis of endomyocardial fibrosis.