Bartonella are hemotropic bacteria that infect humans and a wide range of mammals. Wild and domestic animals represent a large reservoir for Bartonellae and at least 25 species or subspecies of Bartonella have been described and some of them are agents of zoonotic infections. Bartonellae are recognized as vector-borne bacteria. Direct transmission occurs from animal to human by scratching or biting. Three diseases are described in humans: Carrion's disease, trench fever and cat scratch disease. Beside these main diseases, other clinical manifestations occur, due to other Bartonella species. These manifestations are scarce. Diagnosis is performed using serology, pathology, culture and molecular biology. Therapeutic is based on results of antibiotic susceptibility of some strains. Prevention of these infections relies on control of arthropod vector.