Abstract
Tension pneumopericardium is most commonly traumatic. Nontraumatic etiologies are rare, but have been reported with gastropericardial and esophagopericardial fistulas. We present the case of a 54-year-old patient who developed a tension pneumopericardium with tamponade secondary to a perforated marginal ulcer in the proximal jejunum with an enteropericardial fistula. (Level of Difficulty: Intermediate.).