Milk and other lipid containing products are susceptible to oxidative deterioration. Light from either natural or artificial sources catalyzes certain chemical reactions, resulting in the development of off‐flavors and the breakdown of pigments and vitamins. This review deals with the subject of light induced deterioration of foods and its various ramifications. Reaction pathways of light energy in model or natural systems are outlined. Mechanisms are presented, and the roles of lipids, proteins, and vitamins during photochemical reactions are discussed. Damaging effects of light on nutritional and organoleptic quality of milk and several fats or fat containing products are discussed and explained. Ways and means of preventing the occurrence of oxidation defects are covered involving the use of suitable containers and light barrier properties of packaging materials.