Importance: Nasogastric tube (NGT) placement can cause severe thoracic and non-thoracic complications, which can cause severe morbidity and mortality. The knowledge of predisposing factors is crucial for prevention of these complications. Design: We report on three different cases of severe complication of NGT placement, which have not yet been described. Results: In the first case, intrathoracic malposition of a NGT in a sliding gastric hiatus herniation and repeated insufflations of air for localization control resulted in compression and laceration of the lungs with massive pulmonary hemorrhage. In the second, there was a perforation of both the esophagus and the membranous part of the trachea from the gullet site by a guidewire-containing NGT. In the third case, severe pleuropulmonary complications occurred after short-term intrabronchial malposition. Conclusions: These cases are intended to encourage vigilance to reasons and the clinical course of thoracic complications of NGT placement. Predisposing factors and preventive measures are discussed.