OBJECTIVE: Bronchoalveolar lavage (BAL) is indicated in children with inflammatory and non-inflammatory lung disease. BAL may have an important role in reaching specific diagnosis, treatment consideration and  disease course prediction. This study evaluated microorganisms pattern in pediatric patient that had undergone BAL procedure in RSCM, it aims to guide therapeutic decision. 
METHODS: A retrospective study from 2015 to first-quarter of 2019. We collected data about indication and pathogen then tabulated them to show the results.
RESULTS: The main indication for BAL procedure was atelectasis, which reached 75% of examination, followed by pneumonia, bronchiectasis, inhalation trauma, and congenital anomalies of airway. For infection cases, bronchoalveolar lavage (BAL) culture, which is performed in 88.7% of total patients, revealed that Pseudomonas aeruginosa remained a dominant pathogen in our patients (24.4%) which was commonly found in hospital acquired pneumonia (HAP), ventilator associated pneumonia (VAP) that had congenital heart disease as comorbid, inhalation trauma, either in intensive or non-intensive wards. Other common pathogens were Acinetobacter baumanii (11.9%), Klebsiella pneumoniae (10.8%) which was commonly found in lung atelectasis, bronchiectasis, Streptococcus alpha-hemolyticus (5.7%),  Eschericia coli (3.4%), Burkholderia cepacia, Citrobacter freundii, Elizabethkingia meningoseptica, Chryseobacterium indologen, Serratia marcescens, Stenotrophomonas maltophilia (1% for each). The culture was sterile in 5.6% patients and 15% did not show culture results. BAL was not performed in 5.7%  patients with foreign bodies. 
CONCLUSION: Persistent atelectasis and infection continued to be the main indication for BAL examination. Gram negative bacilli, mainly P. aeruginosa, was the main pathogen in our study. As consequences, we think broad-spectrum empirical antibiotics should include anti-Pseudomonas antibiotic as backbone therapy for infected patients.