Most cases of tension gastrothorax have been reported in pediatric patients with congenital defects of the diaphragm or adults with traumatic or surgical loss of diaphragm integrity. Congenital diaphragmatic hernias occur most commonly in the left posterolateral region of the diaphragm in an estimated 1 per 2,000 to 3,000 live births. Typically, severe respiratory distress develops progressing to cyanosis during the neonatal period, with rare cases presenting as late as 14 years of age. In adults with blunt trauma to the abdomen, tension gastrothorax also seems to occur more commonly on the left side, which has been attributed to protection of the right hemidiaphragm by the liver. A traumatic gastrothorax is the result of diaphragmatic rupture that occurs in thoracoabdominal trauma and is usually diagnosed acutely. However, if the abdominal contents do not immediately herniate or the symptoms are not initially recognized, there may be a resulting delay in diagnosis. Interestingly, our patient did not have a history of trauma or major surgery near the diaphragm. Instead, he had a longstanding type III hiatal hernia, and tension physiology developed soon after placement of a jejunostomy tube.