Serologic tests for Lyme borreliosis and for syphilis were performed on 75 patients seen in a 1-week period at the Bascom Palmer Eye Institute in Miami. The incident of syphilis was 8% and of Lyme borreliosis 3% in this study in a nonendemic area. The most common cause for a high titer serologic response for Lyme borreliosis in this group was a prior Treponema pallidum infection. The importance of getting VDRL, FTA-ABS, Lyme IFA, and Lyme ELISA tests in all suspected cases was emphasized.