Between the dates of May 4th - August 6th 2002, 46 cases were detected with abdominal pain nausea, vomiting, arthralgia/myalgia, headache, fever, diarrhea and rash, in the middle Blacksea and north inner Anatolia regions. Their laboratory findings yielded elevated levels of liver enzymes (AST, ALT, LDH), leucopenia and thrombocytopenia. As the infection was treated easily with tetracyclines, clinical diagnosis was considered to be rickettsiosis or ehrlichiosis. Serum and blood samples obtained from some of the patients were tested against Rickettsia, Ehrlichia, Leptospira and Coxiella, in the national and international laboratories. Samples from 19 patients were sent to National Reference Centre and WHO Collaborating Centre for Rickettsial Reference and Research Laboratory, France, and 7 of them were reported as acute Q fever while 8 of them were reported as passed Q fever (QF) cases. In May 2003, new cases with similar symptoms have been reported from the same regions, with different epidemiologic and serologic findings (tick exposure history was higher, response to tetracycline was lower, C.burnetii antibodies were negative), indicating a viral etiology. The samples of these patients have been sent to National Reference Centre and WHO Collaborating Centre for Arboviruses and Viral Heamorrhagic Fevers, France, and the initial reports were marked as Crimean Congo hemorrhagic fever virus (CCHFV). Then the serum samples of previous 26 patients which were stored in National Serum Bank have been retrospectively investigated for viral aetiology in the same center, and 17 of them have been found positive for CCHFV IgM antibodies. Four of these patients were diagnosed as acute QF in 2002, one was passed QF, 2 were negative for QF and 10 were patients not investigated for QF. As a result, the detection of the both infections together in the same area shows the essential need for further epidemiological investigations.