Background: Lower respiratory tract infection (LRTI) is an inflammation of the airways (pulmonary tissue), due to viral or bacterial infection, below the level of the larynx. LRTI includes various diseases such as: bronchiolitis, wheeze-associated LRTI, bronchopneumonia, Lobar pneumonia and Empyema. LRTI is one of the serious illnesses requiring hospitalization especially in children under 5 years of age. It accounts for 30% of deaths annually worldwide mostly due to pneumonia as the leading cause . In the recent decades, pediatric pulmonology has made significant progress in understanding and managing children's respiratory diseases, and has become a specialty in itself. The advancement of diagnostic tools like flexible bronchoscopy (FOB) has greatly contributed to the development of this speciality. The major advantages of the flexible bronchoscope include the ability to insert it nasally, orally or through a tracheostomy to visualize segmental and subsegmental bronchi in all lung lobes. Flexible bronchoscope is a safe and effective tool for evaluation of children with persistent or recurrent pneumonia, where the underlying diagnosis is not clear from non-invasive diagnostic tests. FOB has also therapeutic role in certain diseases such as a foreign body granuloma by cryotherapy or pulmonary alveolar proteinosis (PAP) by a therapeutic BAL.