The Captia Syphilis IgG enzyme immunoassay (EIA) was evaluated for use in conjunction with the rapid plasma reagin test (RPR) as a method to test for syphilis. A total of 1,288 serum specimens were tested by the routine laboratory protocol of the RPR followed by microhemagluttination assay for Treponema pallidum (MHA-TP) testing of RPR-reactive sera as well as the EIA-RPR protocol in which the automated EIA followed by a manual RPR test for EIA-positive specimens is used. When using the routine protocol, 131 specimens were initially reactive by the RPR, and 113 of these were reactive by MHA-TP. When using the EIA-RPR protocol, 170 specimens were initially positive by EIA, and of these, 112 were RPR reactive, indicating active disease. When compared to the routine protocol, the EIA-RPR protocol had sensitivity, specificity, and positive and negative predictive values of 96.5, 99.7, 97.3, and 99.7%, respectively. After resolution of discrepancies by additional testing, the adjusted sensitivity, specificity, and positive and negative predictive values were 100, 99.8, 98.3, and 100%, respectively. This evaluation demonstrates that when used in conjunction with the RPR, the Captia Syphilis EIA is a reliable method by which to test for syphilis.