To clinically characterize the events of anaphylaxis in a third-level pediatric hospital. 1148 clinical records were reviewed. Eventually, the information of 35 events of anaphylaxis in 20 patients was analyzed; three of them had multiple episodes of anaphylaxis. The median age for the anaphylactic episodes was 11 years (Interquartile range 10 years, Q1 = 5, Q3 = 15), predominantly in adolescents between the ages of 12 and 17 years, and there was a slight predominance in women. The most frequent clinical manifestations were cutaneous (86%), followed by respiratory (83%), cardiovascular (74%), and gastrointestinal (46%) alterations. Cardiac arrest was documented in three episodes; however, no anaphylaxis-related deaths were reported. The main triggers for anaphylaxis were food (34%), medications (29%), allergen-specific immunotherapy (14%), and latex (11%). In patients with perioperative anaphylaxis, the clinical behavior was severe. Epinephrine was administered in 27 out of the 35 events (77%), but only in 11 cases it was the first-line treatment. Systemic corticosteroids were the most frequently used treatment, followed by epinephrine and antihistamines. The use of epinephrine, which is the mainstay of the treatment, is suboptimal; with a preferred use of second-line medications like corticosteroids. Clear protocols for the diagnosis and treatment of anaphylaxis, as well as continuous education of health personnel, are necessary.