Background: The prevalence of allergic diseases has risen in the last decades. The objective of this study was to determine the common allergens in children via the skin prick test.Methods: This cross-sectional study recruited 313 allergic children (4 months to 18 years old) referred to the Asthma and Allergy Clinic of Children’s Medical Center in Tehran. A questionnaire containing demographic data and patient history was completed. The Skin Prick Test (SPT) was selected according to the patients’ history of food and/or aeroallergen sensitivity. Results: Patients (62.4% male, 37.6% female) with symptoms of asthma (n=141, 57.1%), allergic rhinitis (n=50, 20.4%), atopic dermatitis (n=29, 11.7%), and urticaria (n=20, 8.1%) were studied. Positive skin prick test to at least one allergen was 58.1%. The most prevalent allergens were tree mix (26%), Alternaria alternata (26%), weed mix (23.6%), Dermatophagoides farinae (22.9%), Dermatophagoides pteronyssinus (22.9%), milk (21.7%), eggs (20%), and wheat flour (18.3%). Also, common allergens in the patients with different symptoms of allergic disorders were as follows: asthma (tree mix, weed mix, and Dermatophagoides farinae); allergic rhinitis (Dermatophagoides farinae, tree mix, and Dermatophagoides pteronyssinus); and atopic dermatitis (Alternaria alternata, Dermatophagoides pteronyssinus, and cockroaches). Conclusion: Identifying allergens in each area is necessary and has an important role in the diagnosis and management of allergic disorders and possibility of performing immunotherapy. In this study, the most common aeroallergens were tree mix, Alternaria alternata, and weed mix and also the most common food allergens were milk, eggs, and wheat. Considering these data, appropriate preventive strategies can decrease the cost and morbidity of therapeutic actions.