Behçet's disease is a chronic, heterogeneous, multisystem disorder caused by a vasculitis involving arterial and venous vessels of all sized. In 1990, a new set of diagnostic criteria has been proposed as a guide to diagnosis of Behçet's disease, requiring the presence of oral ulcerations plus two of the following symptoms or signs: genital ulcerations, characteristics eye lesions, typical skin lesions, and a positive pathergy test. Nevertheless, both clinic and pathologic diagnosis of Behçet's disease remains sometimes very difficult. Diagnostic procedures and therapeutic implications in a case of Behçet's disease are reported and discussed.