Behçet disease is a rare autoinflammatory disorder of unknown aetiology and is characterised by systemic manifestations with an exacerbation-remission pattern, often associated with diagnostic delay. The diagnostic approach to this disease is complex. A report is given on four cases of patients fulfilling the diagnostic criteria for Behçet disease. Other autoimmune rheumatic diseases were considered in the clinical approach. A meticulous clinical evaluation, taking into consideration relapsing aphthous ulcers in oral mucosa and genitalia, and HLA typing allowed a proper diagnosis of Behçet disease to be made.