Computer Assisted Semen Analyses (CASA) is a recent concept to provide information on concentration, viability, morphology and kinematics of spermatozoa, fresh and frozen-thawed, of different mammalian species, and is routinely being employed in human Andrology Laboratories. Presently to some extent it is also being used in Commercial Bovine Frozen Semen Production Laboratories of the world for evaluating the quality of spermatozoa before use in artificial breeding services. It is also made mandatory on such laboratories under minimum standard protocols of concerned Governments. The system provides useful information in numerical as well as percentage values on sperm motility and velocity parameters such as progressive sperm motility, average path velocity, straight line velocity, curvilinear velocity, straightness, linearity, elongation as well as static, slow, medium and rapidly motile sperm proportion of a given semen sample of ox- and buffalo-bulls, both fresh and frozen-thawed semen. There were very good interrelationships among various parameters tested, particularly with progressive motile and hypo-osmotic swelling reactive spermatozoa.