Brucellosis is one of the most common zoonotic diseases that can be encountered during pregnancy. We present two pregnant women with brucellosis. One of them delivered normally and the other patient had an abortion. We reviewed the literature regarding the clinical course of brucellosis in pregnant women. Brucellosis during pregnancy can be associated with abortion, congenital and neonatal infections and infection of the delivery team. Therefore treatment with a combination of rifampicin and trimethoprim-sulfamethoxazole should be started as soon as it is diagnosed to prevent possible complications. © 2010 Japan Society of Obstetrics and Gynecology.