Milk is highly essential food in our life, even if considered as a highly favorable medium for multiplication of different types of microorganisms including disease-producing bacteria as Nocardia species, especially if milk is produced, stored, or handled under poor sanitary conditions. Nocardia species continue to be highly dangerous human pathogens. There is an increase interest of Nocardia species particularly N.asteroides as health risk affecting both human and animal. Also, because of the involvement of milk in human infection. The genus Nocardia was named after Nocard in, 1888 which described a disease of bovine farcy and lymphatic disease of cattle. The members of the genus Nocardia are associated with the group of microorganisms known as the aerobic actinomycetes and belong to the family mycobacteriacae. The Nocardiae contain tuberculostearic acid but differ from the mycobacteriacae by possession of shorter chained [40 to 50 carbon] mycolic acid.