Introduction. Endocarditis is the most common cardiovascular manifestation of brucellosis with high mortality rate. Brucella is less accesable to antibiotic (but not for all) and relapse can occur after a various period of clinical latency. Case report. A 55-year-old farmer was diagnozed with acute systemic Brucella infection in May 2008 and treated with antibiotic therapy in regional hospital for two months and for three months after discharge. He began to feel myalgia, arthralgia, malaise, shortness of breath, abdominal pain, vomiting, diarrhoea and lost weight eight months after initial symptoms occured. Because symptoms progressed he was admitted to our hospital in February 2009. Based on a combination of epidemiological, clinical data (on admission he was catchetic, adynamic, dyspneic, hypotensive 80/50 mmHg, fever up to 39.50C), positive serological Wright test for brucellosis (1 : 5,120), and echocardiographic examination findings, the diagnosis of very severe relapse of brucellosis with mitral valve endocarditis, complicated with perforation of anterior mitral leaflet, severe mitral regurgitation and pulmonary hypertension was established. He was treated with a combined triple antibiotic therapy (vancomycin, ciprofloxacin and gentamicin, and swiched to regimen with doxycycline, gentamicin and imipenem, replacing gentamicin by rifampicin) for 4 weeks and for the next 2 weeks was receiving trimetoprime/sulfamethoxazole and rifampicin. The patients' condition was improved and he was operated. The diagnosis of infective endocarditis was confirmed intraoperatively. Mitral valve replacement was performed, and combined triple antibiotic treatment (amikacin + ciprofloxacin + cefazolin, for 2 weeks and cephazolin + doxycycline + rifampicin, for 2 weeks) was continued, following with two antibiotics (doxycycline + rifampicin) for 5 months. The patient completely recovered without any signs of infection 30 months postoperatively. Conclusion. A combined antibiotic therapy and surgery reduce complications and mortality associated with Brucella endocarditis and improve quality of patients' life.