The natural history of food allergy refers to the development of food sensitivities as well as the possible loss of the same food sensitivities over time. Most food allergy is acquired in the first 1 to 2 years of life, whereas the loss of food allergy is a far more variable process, depending on both the individual child and the specific food allergy. For example, whereas most milk allergy is outgrown over time, most allergies to peanuts and tree nuts are never lost. In addition, whereas some children may lose their milk allergy in a matter of months, the process may take as long as 8 or 10 years in other children. This review provides an overview of the natural history of food allergy and provides specific information on the natural course of the most common childhood food allergies.