A case of aortic valve endocarditis caused by Coxiella burnetii and operated on with success is reported. The patient is doing well at 18 months follow up. Diagnosis of Q-fever endocarditis was made by high antibodies against phase I Coxiella burnetii antigens titration and by demonstration of aortic valvular vegetations by bidimensional echocardiography. Our patient suffered emergency aortic valve substitution due to acute hemodynamic failure and started a long-term treatment with doxycycline and rifampicin. Some interesting aspects about the diagnosis and treatment of this patient are reviewed because long-term follow-up and serological controls are still rare in the literature.