Infective endocarditis(IE), known as an inflammation of the endocardium and the inner lining of the heart and heartvalves, is a life-threatening disease. Although IE is very rare in people with no heart valve disease, the risk increases in those with heart valve disease.The clinical signs and symptoms of infective endocarditis vary considerably. The diagnosis of infective endocarditis is made by according to modified Duke criteria. In this case report,we describe a 23-years old male patient of infective endocarditis misdiagnosed as Crimean-Congo hemorrhagic fever(CCHF) because of he had thrombocytopenia, increased AST-ALT, CK and LDH levels in his laboratuary findings.Thrombocytopenia, increased AST-ALT, CK and LDH levels are the most common laboratory findings in CCHF cases. The patient who hade preliminary diagnosis of CCHF was referred from secondary care hospital with fever of two weeks. It was learned that the patient was previously diagnosed ARA (Acute Rheumatic Fever) in his history. He was diagnosed as MSSA endocarditis on the mitral valve and the patient was operated on because of IE. After the treatment was completed for 6 weeks, the patient was discharged with healing. With this case report we aimed to emphasize that the cases of infective endocarditis could mimic other diseases and detailed physical examination should be performed on all patients.