Brucellosis is known as undulant fever or Malta fever, caused by the genus Brucella. It is the most common human zoonosis. The disease is worldwide distributed and causes significant economic losses. In animals, it causes abortion, reduction in milk production, and infertility. While brucellosis in humans is a debilitating disease with various clinical manifestations that may lead to death in some cases. Control of disease in animals needs proper diagnosis, permanent monitoring of brucellosis-free herds, and removal of infected animals. The current review will discuss the serological and molecular techniques daily used for the determination of brucellosis in animals and humans.