Endotracheal suction plays a major role in providing airway care but it is nor without inherent hazard. In routine practice of pediatric intensive care, the suction catheter is usually inserted until slight resistance is felt and is then withdrawn. Here we report three instance in last year of a rare complication of suction - secondary pneumothorax after bronchial perforation due to deep endotracheal suction. It should always be first suspected in an infant who suddenly deteriorates during or after such suction procedure. Premeasurement of the appropriate depth for catheter insertion, with the tip no more than 1 to 2 cm beyond the carina, is also suggested to minimize or prevent this complication.