Background: Recommendations for the management of anaphylaxis include acute and baseline tryptase measurement. Their implementation has made substantial progress in the context of perioperative anaphylaxis in adult populations, but pediatric data are scarce. We set out to conduct a review of tryptase assessment in pediatric anaphylaxis in a French University Hospital. Method: Retrospective study of suspected pediatric anaphylaxis cases that occurred from 2011 until 2020 in the University Hospitals of Marseille, France. Results: 202 patients experienced ≥ 1 episode of suspected anaphylaxis, documented with ≥ 1 tryptase determination; 18/202 experienced ≥ 2 episodes. Perioperative anaphylaxis (POA) was suspected in 36 patients (37 events); emergency department anaphylaxis (EDA) accounted for 110 patients (118 events) and various hospital wards (HW), mainly allergology and intensive care, for 58 patients (68 events). The age range was 0–18, with median (IQR) at 12.0 (2.8–16) in POA, 9.5 (2.0–13.0) in EDA, and 8.3 (2.6–12.0) in HWA, nonsignificant. Boys were non significantly predominant in POA (76%) and in EDA (60%) but not in HWA (50%). A second (“post-acute”) tryptase determination was performed in 18/37 (49%) POA, 103/118 (87%) EDA, and 50/68 (74%) HWA, P < 0.0001. With the 1.2*sBT + 2 algorithm, mast cell degranulation was confirmed in 6/18 (33%) POA, 40/103 (39%) EDA, and 10/50 (20%) HWA, p = 0.0067. Among patients with ≥ 1 suspicion of anaphylaxis, post-acute tryptase determination was lacking in 10 and exhibited a median of 4.2 µg/L (range 3.1–4.6) in the 8 others. Post-acute tryptase values were ≥ 6 µg/L in 2/18 (11%) POA, 30/103 (29%) EDA and 10/50 (20%) HWA, but inadequate sampling timing, less than 24h after complete resolution, prevents discussion of hereditary alpha-tryptasemia. sAT levels were higher in EDA 6.6 (3.8–12) v. POA 4.5 (2.6–7.7) and HWA 4.6 (3.3–7.2), P < 0.05. Conclusion: The use of anaphylaxis management recommendations is less followed in child populations, as shown by the low figures of post-acute tryptase sampling in POA, at 49% in this study. The use of sequential tryptase determinations in EDA, with 87% of patients receiving a second determination, resulting in mast cell degranulation confirmation in 39% of cases. We also found that sAT values were significantly higher in EDA than in POA or HWA, suggesting that time elapsed between the onset of anaphylaxis and arrival at ED does not preclude adequate tryptase sampling and mast cell degranulation assessment.