Yersinia enterocolitica-derived heat-shock protein (HSP60) was recently demonstrated to be associated with certain systemic autoimmune diseases. A role for HSP60 is also suspected in the pathogenesis of some types of uveitis believed to involve autoimmune mechanisms, such as Behçet's disease. We report our results on the role of HSP60 in patients with uveitis. HSP60 was subjected to electrophoresis in immunoblot analysis, and then allowed to react with sera from patients with uveitis in order to detect the presence of anti-HSP60 antibody. Tissue extracts from human and bovine retina were also electrophoresed, and then treated with anti-HSP60 monoclonal antibodies to determine whether or not the antibodies recognized ocular tissues. Immunoblot analysis revealed anti-HSP60 antibodies in patient sera. Furthermore, anti-HSP60 monoclonal antibodies reacted against the 60-kD protein derived from human and bovine retinal extracts. These immunological cross-reactions between HSP60 and the retina demonstrate a common antigenicity. Furthermore, detection of specific antibody against HSP60 in patient sera suggests that this common antigenicity between HSP60 and the retina may be related to the pathogenesis of uveoretinitis in some cases.