Between 1981 and 1994, the detection of specific antibodies against Toxoplasma gondii was performed simultaneously in serum and aqueous humor from 90 patients, and the Witmer-Desmonts coefficient measuring the relative concentration of antibodies produced locally was calculated to confirm the clinical diagnosis of ocular toxoplasmosis. Thirty-seven results were positive (41.1%), 12 uncertain (13.3%) and 41 negative (45.6%). These results are compared with the data obtained by the polymerase chain reaction for the genomic detection of an infectious agent in the aqueous humor that have recently been published.