Recently, assays that can distinguish between antibody to herpes simplex virus (HSV) types 1 and 2 have become available. These tests not only make it possible to better define infection in symptomatic patients and their sexual partners but also to identify asymptomatic infected individuals who may, nevertheless, be infectious. Type-specific antibody tests for HSV have several potential applications. They have a clear role in helping to define the worldwide distribution and pattern of HSV infection, and a potential role in the management of individual patients, although this has yet to be formally established and evaluated. Because of the high costs and potential disadvantages of targeted screening, particularly in the absence of effective interventions to prevent acquisition or transmission of infection, the public health benefits of screening need to be formally evaluated before its widespread introduction.