HLA antigen frequencies were studied in 20 patients with ocular cicatricial pemphigoid and 245 normal persons. HLA-B12 demonstrated an increased frequency of 45% in patients with ocular cicatricial pemphigoid which was statistically significant when compared to a frequency of 19.6% in the general population (P less than 0.02). In patients with ocular cicatricial pemphigoid the prevalance of HLA-A3 was increased to 35% when compared to 22.9% in the general population, but this was not statistically significant. The frequency of finding either HLA-A3 or B12 in patients with ocular cicatricial pemphigoid was increased to 75% in comparison with 38.8% in the general population (P less than 0.005). The present study suggests that HLA-B12 and possibly HLA-A3 are genetic markers for ocular cicatricial pemphigoid.