Aseptic packaging involves the filling of a commercially sterile product into sterile containers under sterile conditions and sealing the containers so that reinfection is prevented. Over 35 billion liters of milk products are aseptically packaged annually. The three main sterilization processes for packaging materials involving radiation, heat, and chemical treatments are discussed. The four main categories of aseptic packaging systems (cartons, plastic bottles, sachets and pouches, and cups) and their major features and characteristics are described.