Uveitis can be a serious complication of leptospirosis. Previous studies indicated that the leptospiral lipoproteins LruA and LruB are expressed in the eyes of uveitic horses and that antibodies directed against those proteins show in vitro cross-reactivity with components of equine lens, ciliary body, and/or retina. We now demonstrate that sera from a significant proportion of humans who have leptospiral uveitis also contain antibodies against LruA and LruB. Different categories of nonleptospiral uveitis and autoimmune uveitis were also screened; patients diagnosed with Fuchs uveitis or Behçet's syndrome produced antibodies that cross-reacted with LruA and LruB, suggesting similarities of the autoimmune responses in those diseases with those of leptospiral uveitis.