Upper airway obstruction is a potentially fatal condition that requires prompt diagnosis and treatment. Common causes include foreign body aspiration, infections (even in the adult population) and sequelae of intubation, tracheostomy, and transtracheal oxygen catheters. Spirometry is an insensitive test for diagnosing upper airway obstruction and reflects the functional, rather than anatomic, severity of an obstruction. Although simple tomography still plays an important role, CT and magnetic resonance imaging scans are useful additions to our diagnostic armamentarium. Advances in laser technology, surgery, and bronchoscopy have broadened treatment options but require further evaluation.