Cytomegalovirus infections are a major source of morbidity and mortality in immunocompromised patients. We report a case of cutaneous cytomegalovirus in a patient with the acquired immunodeficiency syndrome, in which routine light microscopy was suggestive but not diagnostic of cytomegalovirus. Immunohistochemical studies of the specimen for cytomegalovirus antigens revealed numerous intracytoplasmic and intranuclear viral inclusions. This case illustrates the utility of immunoperoxidase techniques to diagnose cytomegalovirus infection of the skin rapidly. Immunohistochemistry, DNA in situ hybridization, and polymerase chain reaction have been added to the more routine methods of viral culture and light microscopy to diagnose cytomegalovirus. In this report we review the cases of cutaneous cytomegalovirus in the literature and the laboratory detection methods available to establish this diagnosis.