Brucellosis is a zoonosis and caused by several species of Brucella. Brucellosis is especially prevalent in in the Mediterranean countries of Europe, north and east Africa, the Middle East, south and central Asia and Central and South America. In Korea, it was 2002 when the first official case of human Brucellosis was confirmed. Since then, the number of human Brucellosis is dramatically increasing. The infection is transmitted by direct or indirect contact with infected animals or their products. Brucellosis is an acute or sub-acute febrile illness usually marked by an intermittent or remittent fever accompanied by malaise, anorexia and prostration. The most common organ involvement is bone and joint. Reproductive system is the second most common site. Unilateral epididymo-orchitis is the usual complication in reproductive system in men. Prostatic involvement of brucellosis is very rare and shows granulomatous prostatitis. We report a case of biopsy-proven granulomatous prostatitis due to Brucella abortus in Korea.