Introduction: Anaphylaxis is an emergency condition. According to the latest international guidelines, early recognition and treatment with intramuscular epinephrine are associated with increased survival. Objective: To determine the level of knowledge of pediatricians in a tertiary Pediatric Hospital about the diagnostic criteria and treatment of anaphylaxis. Material and Method: A cross-sectional descriptive study was conducted, designing, applying, and validating an anonymous survey to physicians with complete residency in pediatrics who are on call at a third level hospital. The statistical analysis was made using the SPSS v.21 software, presenting measures of central tendency (median, range, and frequency table) and Chi-square test for comparison. A value of p < 0.05 was considered significant. Results: 71 physicians completed the survey with a median of three years after the end of residency. 35% of them identified all clinical criteria, 99% (70) indicated epinephrine, 73% chose the intramuscular route, and 55% indicated the correct dose. Only 48% of responders chose the dose and administration route correctly. In general, 21% recognized anaphylaxis and used epinephrine correctly. Physicians with less than five years of experience performed better in the intramuscular administration of epinephrine (83% vs 52% p = 0.005) and in the detection of gastrointestinal symptoms (60% vs 35% p = 0.043). Conclusions: There are difficulties in the identification and proper management of anaphylaxis by pediatricians of a tertiary Pediatric Hospital in a theoretical clinical setting. Although most of pediatricians chose epinephrine as a first-line drug, half of them did not indicate it correctly, and only one-third recognized anaphylaxis in all scenarios.