Serologic tests for antibodies to herpes simplex virus (HSV) have traditionally played a limited role in the treatment of patients with genital herpes. The epidemiological gold standard has been the Western blot analysis, which is only available in a few research centers and is expensive. The gold standard of diagnosis for HSV infection has been viral culture. Diagnosis by viral culture has severely underestimated the number of individuals infected. The majority of patients who are seropositive for herpes simplex virus type 2 (HSV-2) by Western blot analysis are unaware of their symptoms (unrecognized infection) or have subclinical infection. These patients are unlikely to present for culture. Enzyme-linked immunosorbent assay (ELISA) for the serologic diagnosis of herpes has been available for many years but suffers from poor sensitivity and specificity. Reliable, convenient serologic tests for antibodies that distinguish between prior infection with HSV-1 and HSV-2 have recently become commercially available.