OBJECTIVE: Children often present to the pediatric emergency department (ED) with a reported penicillin allergy. The true incidence of pediatric penicillin allergy is low, and patients may be inappropriately denied first-line antibiotics. We hypothesized that more than 70% of reported penicillin allergies in the pediatric ED are low risk for true allergy. M METHODS: Parents of children presenting to the pediatric ED with parent-reported penicillin allergy completed an allergy questionnaire. The questionnaire included age at allergy diagnosis, symptoms of allergy, and time to allergic reaction from first dose. The allergy symptoms were dichotomized into high and low risk in consultation with a pediatric allergist before questionnaire implementation. RESULTS: A total of 605 parents were approached; 500 (82.6%) completed the survey. The median (interquartile range) age of the children at diagnosis was 1 year (7 months, 2 years); 75% were diagnosed before their third birthday. Overall, 380 (76%) (95% confidence interval 72.3, 79.7) children had exclusively low-risk symptoms. The most commonly reported symptoms were rash (466, 92.8%) and itching (203, 40.6%). Of the 120 children with one or more high-risk symptom, facial swelling (50, 10%) was the most common. Overall, 354 children (71%) were diagnosed after their first exposure to penicillin. Symptom onset within 24 hours of medication administration occurred in 274 children (54.8%). CONCLUSIONS: Seventy-six percent of patients with parent reported penicillin allergy have symptoms unlikely to be consistent with true allergy. Determination of true penicillin allergy in patients with low-risk symptoms may permit the increased use of first-line penicillin antibiotics.