Tracheal rupture after endotracheal intubation is a rare but serious complication. Its causes remain unclear but many physicians believe that weakness of the membranous trachea in patients with chronic illness is a leading factor. We present three patients who developed membranous tracheal rupture after emergent endotracheal intubation. Based on our experience and a review of the relevant literature, we emphasize selection of a correctly sized endotracheal tube to minimize the risk of rupture. Use of a smaller endotracheal tube in the emergent setting, especially for patients at potential risk of rupture due to steroid use or chronic illness, is highly recommended.