The illness of Behçet is a multissistemic pathology with chronic evolution, presenting, sometimes outbreaks of acuteness. Diagnosis is essentially clinical provided following manifestations are present: muco-cutaneous, uro-genital, blood vessel, articulations and/or neurological disorders. The author tells a case of a female patient, 31 years old, with a history of recurrent oral and genital ulcers and cutaneous injuries. This particular insufficiency of symptoms required research of disgnostic criteria, due to the absence of the triple symptomatic complex, including repetition’s iritis, not present in this case. Diagnosis was made according to criteria of Behçet syndrome. Treatment then began with full remission of injuries after two weeks. The objective of this report is to remark the importance of scientific knowledge of diagnostic criteria, above all when in presence of rare illness.