Adamanitiades-Behcet's disease (ABD) is a relapsing systemic vasculitis that may involve the eyes, skin, and almost all other organ systems. Current research on the pathogenesis of ABD suggests a genetic basis for the disease, with certain MHC genes such as those coding for HLA-B51 being the most obvious candidates. Environmental factors such as infectious disease are thought to be responsible for triggering an immunological reaction and systemic features of the disease in genetically susceptible individuals. Identification of genes responsible for this susceptibility may lead to more definitive diagnostic tests and new approaches to the management of this potentially blinding condition.