Intubation stylets are still being used in many medical centers for difficult intubations. Although very rare, it may break inside the trachea during endotracheal intubation despite routine pre-assessments by anesthesiologists and may surprisingly move deep into the tracheobronchial tree. In this case report, we describe a rare complication after stylet or guide-wire intubation in a patient in whom, a broken piece of metal guide remained in his tracheobronchial tree for 3 days. A 62 year-old man was admitted to our hospital with the chief complaint of functional class 3 dyspnea. The patient was a known case of chronic obstructive pulmonary disease (COPD) from 3 years ago with a history of heavy smoking (40 p/y) and oral opioid usage. We report a case with an unrecognized broken piece of stylet in his trachea and left main bronchus, which was later detected by CT scan and extracted before causing pressure rise symptoms in the airway. Despite precise evaluation before use, signs of breakage in the stylet may be missed and consequently, it may break inside the trachea and result in serious complications. It is strongly recommended that the anesthesiologists pay attention to the sounds and movements of the instruments. This article also briefly reviews the most serious reported complications due to stylet breakage.