Rickettsialpox is a rare mite-borne rickettsiosis that is encountered in urban populations in the eastern United States and throughout the world. It is characterized clinically by an eschar, fever, and a papulovesicular eruption. Both of these cutaneous manifestations may be mimicked by infectious diseases that have been designated as bioterrorist agents by the United States Centers for Diseases Control and Prevention: the former by anthrax, and the latter by smallpox. It is thus important for clinicians to be familiar with rickettsialpox. We report 3 cases and review the epidemiology, clinical and laboratory findings, differential diagnosis, and management of this disease.