The rickettsial group of bacteria causes several infections known as spotted fevers. Rocky Mountain spotted fever (RMSF) caused by Rickettsia rickettsia is the most common tick-borne rickettsial infection in the United States. Most cases are seen in the summer months. RMSF presents with fever, headache, and a characteristic purpuric rash. Empiric treatment should be considered in possible cases, and doxycycline is the drug of choice. The most commonly used diagnostic test is an indirect immunofluorescence assay, which may be nonreactive early in illness. Other rickettsial infections, such as rickettsialpox and Rickettsia parkeri infections, present with fever, headache, and a skin eschar. Diagnosis requires a high index of suspicion as symptoms may be nonspecific earlier in the course of infection. Doxycycline is the treatment of choice for all the rickettsiae.