Objective. A management protocol for infants hospitalized for acute bronchiolitis, established after the study conducted in our unit in 2012, recommends a chest X-ray when the clinical course is unusual or if a differential diagnosis is suspected. The goal of this study was to evaluate professional practices after the introduction of this new management protocol. Study design. Retrospective descriptive study in two pediatric units from October 2013 to March 2015, including infants (0-23 months) hospitalized for their first episode of acute bronchiolitis without any underlying chronic condition. Result. Overall, 599 infants were included (median age, 3.7 months, 54 % boys). Nearly six out of ten (n = 355, 59.3 %) had at least one chest radiograph (38.5 % fewer than in 2012). It was abnormal in 96.3 % of cases, revealing distension and/or bronchial wall thickening (56.7 %), focal opacity (23.5 %), or atelectasis (19.5 %). An X-ray was performed out of the recommendations in 42.5 % of cases. The chest X-ray result led to management changes in 52 infants with prescription of antibiotics for pneumonia (86.5 %) and allowed the diagnosis of heart disease in one case (0.2 %). Management of acute bronchiolitis (X-ray and antibiotics) was statistically different between the two pediatric units. Discussion. This protocol led to a significant decrease in the number of chest X-rays. However, many are still performed out of the recommendations, resulting in an increase of antibiotic use for pneumonia. Conclusion. The decrease in use of chest X-rays in acute bronchiolitis for hospitalized infants was significant but remains insufficient. (C) 2016 Elsevier Masson SAS. All rights reserved.