A 37-year-old patient had fever, diffuse maculopapular rash and acute suppurative arthritis of both knees, which was totally cured with doxycycline without sequelae. Skin biopsy showed characteristic findings of rickettsiosis. In the serological investigation the Weil-Felix reaction was positive and antibodies against Rickettsia typhi but not against Rickettsia conorii were detected by indirect immunofluorescence. No similar case has found in the reviewed literature.