A family study on the inheritance of HL-A antigens and susceptibility to acute anterior uveitis is reported. In the 4 families examined, the antigen 27 (haplotype 2.27) occurred in all of the 7 patients with acute anterior uveitis and in 22 of the 33 healthy family members examined. It is suggested that in Finns the haplotype 2,27 is linked with genes predisposing the carrier to acute anterior uveitis.