The association between HLA-A29 and birdshot chorioretinopathy is the strongest association between HLA and disease ever described. The determination of HLA-A29 is therefore of diagnostic significance. The association between HLA-B27 and acute anterior uveitis (AAU) is much weaker. However, it is evident that B27+ AAU is clinically different from B27-AAU. Half of the B27+ AAU patients have or will have ankylosing spondylitis or Reiter's syndrome. The determination of HLA-B27 is therefore of clinical significance and should be determined in each case of AAU. The B27+ patients should be referred to a rheumatologist. The determination of HLA-Bw51 is of limited but significant diagnostic value for the diagnosis of Behçet's disease in countries around the Mediterranean Sea or Japan. In Northern Europe HLA-Bw51 determination will not give much practical information. The structure and function of HLA class I molecules is now known. It is probable that HLA-A29 and HLA-B27 molecules are directly involved in the pathogenesis of respectively birdshot chorioretinopathy and AAU.