Between April 1987 and October 1992, six cases of Brucella endocarditis were operated on in the authors' hospital for valve replacement. They were five men and one woman with a mean(s.d.) age of 52(15) years (range 30-71 years). Three patients were in New York Heart Association (NYHA) class III and three in class IV. Two patients had previous history of rheumatic fever, one was a drug abuser, two had peripheral embolism and one constrictive pericarditis. Most were living in rural areas. Echocardiographic diagnoses were: severe aortic regurgitation in two patients, mixed disease in two and double valve involvement in two. Valve vegetations were demonstrated in two patients, valve calcification in two and annulus abscess in two others. Serological tests were positive in all patients. All patients had valve replacements and three were operated on as emergencies. Surgical findings were: valve vegetations in two patients, cusp perforation in two annulus abscess in two and prosthetic leak in two. Mean(s.d.) cardiopulmonary bypass time was 123(77) min with a mean ischaemic time of 79(43) min. All patients were given specific antibiotic treatment after surgery. There was no intraoperative mortality and the 5-year survival rate was 100%. Early reoperations were needed in three patients, two because of prosthetic leakage causing severe regurgitation and one for tamponade. The results suggests that Brucella endocarditis is rare, but still occurs in Mediterranean areas. Surgical replacement is needed in spite of antibiotic treatment and recurrences with prosthetic leaks are usual.