Brucellosis (infection with Brucella spp.) is a common zoonosis in many parts of the world. Human brucellosis is a multisystem disease that may present with a broad spectrum of clinical manifestations. Treatment of brucellosis must effectively control acute illness and prevent complications and relapse. The choice of regimen and duration of antimicrobial therapy should be based on the presence of focal disease and underlying conditions which contraindicate certain specific antibiotics. The regimen of first choice is combination therapy with doxycycline for 45 days and streptomycin for 14 days. Gentamicin or netilmicin for the first 7 days may be substituted for streptomycin. Second-choice regimens consist of combinations of doxycycline and rifampicin (rifampin) for 45 days, or monotherapy with doxycycline for 45 days. Surgery should be considered for patients with endocarditis, cerebral or epidural abscess, spleen abscess or other abscesses which are antibiotic-resistant. Tetracyclines are generally contraindicated for pregnant patients and children < 8 years old. Rifampicin 900 mg once daily for 6 weeks is considered the drug of choice for treating brucellosis in pregnant women. In children < 8 years old the preferred regimen is rifampicin with cotrimoxazole (trimethoprim-sulfamethoxazole) for 45 days. An alternative regimen consists of a combination of rifampicin for 45 days with gentamicin 5 to 6 mg/kg/day for the first 5 days.