Recuirrent aphthous ulceration of the mouth is common, its aetiology is unknown, and treatment is unsatisfactory.A small proportion of persons with this complaint also suffer recurrent ulceration of the genitalia.A still smaller fraction of these persons develop serious ocular complications at some stage in the illness.Recurrent oral and genital ulceration together with hypopyon iritis constitute the " triple symptom complex " of Behcet.Several authors accept two of the three manifestations as criteria for the diagnosis of Behcet's syndrome (Berlin, 1944; Phillips and Scott, 1955; Curth, 1956; Wadia and Williams, 1957).