In 1980 Ryan and Maumenee described a new clinical entity characterized by hypopigmented spots in a typical patterned distribution in association with vitritis and retinal vasculopathy leading to cystoid macular oedema and papilloedema. In a recent study of a large group of European patients (n = 102) with birdshot retinochoroidopathy, the importance of the different clinical manifestations and their diagnostic value were assessed. Data on HLA-A29 typing were obtained in 49 patients with birdshot retinochoroidopathy. We could confirm the high association between HLA-A29 and this disease, as found by Nussenblatt in 1982. In 47 of these patients (95.5%) the HLA-A29 antigen was present. This association is presently the highest HLA class I disease association reported with a relative risk of 224.35.