ood allergies constitute a major public health concern, and the prevalence of food allergies over the past decade has doubled. [1][2][3][4] Foods that most commonly cause allergic reactions include milk, eggs, peanuts, tree nuts, shellfish, fish, wheat, and soy. [2][3][4][5][6][7][8][9] Peanuts account for the most food-induced anaphylaxis and fatal reactions. 4,10,11 Furthermore, the reported prevalence of peanut allergy has nearly tripled in the last 10 years. 2,4,6,9 Peanut allergy occurs early in life, and based on published reports, 18.3% to 21.5% of children may outgrow their peanut allergy. 12,13 Thus, the persistence of peanut allergy is a concerning issue.Since the 1990s, studies have provided evidence that led to guidelines on the timing of peanut introduction. In 1999 and 2000, guidelines from the European Society for Pediatric Allergology and Clinical Immunology, the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN), 14 and the American Academy of Pediatrics (AAP) Committee on Nutrition 15 suggested delaying the introduction of peanut. However, because of the increasing prevalence of peanut allergy, more studies, including the more recent Learning Early About Peanut Allergy (LEAP) 16 study and the Effect of Avoidance on Peanut Allergy After Early Peanut Consumption (LEAP-On) 17 study, report convincing evidence suggesting that early peanut introduction can help reduce the incidence of peanut allergy (Table ). These studies highlight the potential of an early peanut introduction to prevent peanut allergy and provide evidence to support recent recommendations on the timing of peanut introduction.This review discusses the earlier guidelines, highlights challenges to those guidelines, and reviews the new recommendations on early peanut introduction.