AbstractThis chapter deals with the different causes of reproductive diseases in cattle. Focus is given to infectious causes such as Mycoplasma spp., Ureaplasma spp., H. somni, Campylobacter and Trichomonas. The geographical distribution, epidemiology, host range, biology, disease course, pathology, diagnosis, treatment, control and prevention of Mycoplasma bovigenitalium and Ureaplasma diversum are discussed.