Pneumoperitoneum is traditionally considered a surgical emergency suggestive of hollow viscus perforation. However, rare non-surgical causes such as thoracic air leaks may also result in free intraperitoneal air. We report a case of a 16-year-old male who presented with spontaneous right-sided pneumothorax secondary to septic pulmonary emboli and subsequently developed pneumoperitoneum due to trans-diaphragmatic air dissection. The patient was critically ill with sepsis and septic shock requiring intensive care and multiple vasopressors. Contrast-enhanced computed tomography (CECT) of the abdomen revealed pneumoperitoneum without evidence of gastrointestinal perforation. The patient was managed conservatively with chest tube drainage, antibiotics, and supportive care, with favorable outcome. This case highlights the importance of recognizing thoracic causes of pneumoperitoneum to avoid unnecessary surgical intervention.
