Bioactive peptides derived from milk proteins are currently of great scientific interest due to their beneficial health properties. The group of bioactive peptides most studied up until now are the angiotensin-I converting enzyme inhibitory (ACEI) peptides, which, when administered orally, seem to possess the capacity to lower blood pressure in hypertensive subjects. The various techniques of separation, identification, and classification of bioactive peptides obtained from milk and milk products, permit the selection of molecules with the highest level of health benefits to be used as a functional ingredient in the production of milk products with blood pressure-lowering effects such as Evolus((R)) or Calpis((R)). This review focuses on the major research in the areas of isolation, identification, and application of bioactive peptides with ACEI activity in milk proteins, paying special attention to in vitro, in animal model systems, and in clinical studies of hypertensive patients.