The clinical features of 60 patients (45 male, 15 female) with Behçet's disease (BD) are reported in this prospective study. Ninety seven per cent had mouth ulceration, 83% genital ulceration, 75% skin lesions, 48% ocular involvement, 48% synovitis, 17% thrombophlebitis, and 22% of the male patients had epidiymitis, while constitutional symptoms were reported by 63%. The arthritis was intermittent, self limiting, and non-destructive, involving large joints, mainly the knees and ankles. The pathergy test was positive in 37 of 52 patients with BD, and negative in all 120 healthy controls and in 20 healthy volunteers who possessed the HLA-B51 antigen. HLA-B51 was present in 32 of 52 (62%) patients with BD compared with 51 of 175 (29%) unrelated normal controls. Both the pathergy and HLA-B51 tests were negative in four of 52 patients with BD. Behçet's disease is not uncommon in Iraq. Practising physicians, dermatologists, and ophthalmologists must be more aware of its existence.