Paratracheal cysts are a common finding on CT scan. In the setting of trauma, they can mimic pneumomediastinum. The nature of the paratracheal cyst is diverse, however they could be considered to be tracheal diverticula. We report a case of trauma with the incidental finding of a cyst in the thoracic outlet and how this may affect the work up for trauma. It is important that emergency physicians be mindful of this finding especially in the setting of trauma. The anatomic location of the cysts may complicate certain procedures such as central venous catheterization of the internal jugular vein.