Since the type of herpes simplex virus (HSV) infection affects prognosis and subsequent counseling, type-specific testing to distinguish HSV-1 from HSV-2 is always recommended. Although PCR has been the diagnostic standard method for HSV infections of the central nervous system, until now viral culture has been the test of choice for HSV genital infection. However, HSV PCR, with its consistently and substantially higher rate of HSV detection, could replace viral culture as the gold standard for the diagnosis of genital herpes in people with active mucocutaneous lesions, regardless of anatomic location or viral type. Alternatively, antigen detection-an immunofluorescence test or enzyme immunoassay from samples from symptomatic patients--could be employed, but HSV type determination is of importance. Type-specific serology based on glycoprotein G should be used for detecting asymptomatic individuals but widespread screening for HSV antibodies is not recommended. In conclusion, rapid and accurate laboratory diagnosis of HSV is now become a necessity, given the difficulty in making the clinical diagnosis of HSV, the growing worldwide prevalence of genital herpes and the availability of effective antiviral therapy.