During the last two or three decades, a new field of research have arised which deals with bioactive or biogenic substances derived from foods. Bioactive substances could be delivered to the consumer in conventional foods, dietary supplements or certain functional foods. One of these substances is the bioactive or biologically active peptides (BAP). These peptides were defined as food components which may exert a regulatory activity in the human organism, irrespective of their nutritive functions. The present paper surveys BAP that were derived from milk proteins, particularly BAP that were derived from casein as the main milk protein, rather than whey proteins. Furthermore, a general overview is given of the nutritional aspects of human milk proteins and the associated BAP. Finally, there is a focus on infant formula, especially its protein and mineral content and its humanisation to simulate human milk. The application of BAP in the manufacture of such formula is also reviewed.