Background: Wheezing in infants and children is a common problem presented to primary care offices. Approximately 25 to 30 percent of infants will have at least one episode of wheezing. By three years of age, an episode of wheezing will have occurred in 40 percent of children, and by six years of age, almost one half of children will have at least one episode of wheezing. Most infants and children with recurrent wheezing have asthma, but other causes should be considered in the differential diagnosis. The most common diagnoses in children with persistent wheezing are asthma, allergies, gastroesophageal reflux, infections, foreign body aspiration and bronchopulmonary dysplasia. Objective: the present study was designed to evaluate the clinical role of different types of bronchoscope and bronchoalveolar lavage in diagnosis of undefined persistent wheezy chest among the age group from 6 months to 14 years, at Al-Azhar University Hospitals in Cairo. Patients and Methods: This a prospective study was conducted on 50 children complaining from different respiratory problems who had enrolled consecutively from the Outpatient Clinic and the Inpatient Pediatric Department of Al-Azhar Faculty of Medicine University Hospitals (AL-Hussein and Bab-Elshareya), from January 2017 to December 2018. Patients ages ranged between 6 months and 14 years. Results: as regard distribution of patients according to post bronchoscopy diagnosis, the study showed that foreign body inhalation n16 (32%),  Chronic aspiration n9 (18%), tracheobronchomalacia  n2 (4%), bronchial mass  n1 (2%),  streptococcus pneumonia  n7 (14%), hemophilus influenza  n2 (4%), staphylococcus aureus n3 (6%) and pseudomonas aeuroginosa  n2 (4%), candida albicans  n1 (2%), Mycobacterium TB  n1 (2%). Conclusion: It could be concluded that if radiography is normal and the child continues to wheeze, bronchoscopy should be the next step, the bronchoscope is a valuable tool in the diagnosis and treatment of airway disorders in children. It has a good safety profile with rarely reported life threatening or long-standing complications.