HLA-DR typing was performed in 58 Japanese patients with sarcoidosis. We found a significantly increased frequency of HLA-DRw52 (p less than 0.0007; pc less than 0.009) and DR5J (p less than 0.004; pc less than 0.05). (Corrected probability value is given as pc.) In 34 of 58 patients the disease resolved spontaneously. There was no significant difference between the frequency of DRw52 and the resolution rate of disease. The frequency of DR5J was increased significantly in the unresolved cases. Our results also suggest that DRw52 is concerned with onset of sarcoidosis and DR5J antigen has an effect on the clinical course of this disease.