Allergic diseases, such as asthma, allergic rhinitis, eczema, and food allergy, are preventable diseases. Primary prevention strategies of allergic diseases have been in scrutiny. Effective prevention strategies maybe started prenatally, postnatally, during infancy, and even during childhood. These guidelines have been prepared by the Philippine Society of Allergy, Asthma and Immunology and the Philippine Society for Pediatric Gastroenterology, Hepatology and Nutrition. They aim to provide evidence-based recommendations for the dietary primary prevention of allergic diseases in children. The primary audience of these guidelines is all healthcare practitioners who manage patients with potential allergic conditions. These guidelines are based on an exhaustive review of evidences, mostly systematic reviews, randomized controlled trials, and cohort studies. However, there are still many gaps in the evidence of dietary primary prevention of allergic diseases.