Purpose. To determine the role of Bartonella henselae in intraocular inflammatory disease and identify its clinical features. Methods. We retrospectively determined the serum immunoglobulin (lg)G and IgM antibodies against B. henselae and Bartonella quintana by enzyme immunoassays in stored sera of 138 consecutive newly referred patients with uveitis who, during the acute stage of their ocular disease, underwent a standardized screening protocol to determine the cause of uveitis. Results. For the entire series, the frequency of high positive levels of IgG (above 1:900) or IgM (above 1:300) antibody against B. henselae was 6% (8/138) and 3% (4/138), respectively. Except for cross-reactions between B. henselae and B. quintana, we did not find additional evidence for cross-reactions among the various bacteria tested (Coxiella burnetii and Chlamydia pneumoniae). All patients with proven infectious uveitis (n = 21) and those with established uveitic entities (n = 37) had negative B. henselae serology. High positive IgG levels were observed in 9% of patients (5/54) with unknown cause of uveitis, in two subjects with human leukocyte antigen (HLA)-B27 positive uveitis, and in one with sarcoidosis. Five patients with uveitis of unknown origin and highly elevated IgG levels against B. henselae exhibited clinical features characterized by papillitis with surrounding retinal focal lesions or edema. Conclusions. The serologic and clinical data indicate that uveitis in seropositive cases may be caused by B. henselae. We do not recommend including testing for B. henselae in initial screening of patients with uveitis, but consider it worthwhile for those with papillitis and screening results within normal limits.