Introduction: Systemic corticosteroids are widely used in patients with acute bronchial obstruction (ABO). It has been recommended that such treatment last a maximum of 5 days to avoid adverse effects. Suppression of the adrenal axis under these conditions among children has not been evaluated. Objective: Assessment of the hypothalamic pituitary adrenal axis (HHS) function after use of systemic steriods in children after a 5-7 day use of corticoids, utilizing the micro ACTH test. Method: Prospective observational study conducted in the Department of Pediatrics, Hospital Clínico Universidad Católica de Chile. ACTH test used with microdosis (1 mcg/1.73 m²). A normal response was determined if cortisol post-ACTH > 20 mcg/dL. Results: 7 patients were recruited, median age was 4 years 4 months (range 4 months to 8 years). The test was perfomed within an average of 72 hours after discontinuation of prednisone. All patients had normal basal cortisol values, with an average value of 6.5 mcg/dl, range 1 to 9 mcg/dl. The ACTH test yielded a response of cortisol levels with an average value of 13.6 mcg/dL and a range of 3.7 to 20 mcg/dL. Five of the 7 patients presented an abnormal response. Conclusions: Our results suggest that the adrenal response may be reduced in children who have been treated with systemic steroids for ABO even if managed during short periods of time.