Dairy farming is one of the important agro based industry which is not only able to bring a good income for the farmer but also provide an employment throughout the year. Mastitis is the inflammation of the mammary gland affecting all the species of domestic animals and is of great concern to the dairy industry. Mastitis is very common in cows of both developed and developing countries. The dairy industry is facing a great set back due to high prevalence and incidence of mastitis in milch animals. The book includes introduction, Economics of disease, Pathogenesis, Epidemiology, Molecular methods in identification of bacteria in mastitis, Treatment and Control, Epidemiology and characteristics of Staphylococcus aureus intramammary Infection and References.