Tracheal and bronchial diverticulum is a rare benign entity,characterized by round or spherical outpouchings of the tracheal and bronchial wall. Tracheal diverticulum is commonly seen on right side,containing air or fluids.The development of new techniques such as thin-layer CT and multidetector computed tomography have led increasingly reports of incidental findings of this entity. This paper reviews the classification,diagnosis and therapy of this entity.