We describe a child in cardiac arrest with severe ventilatory compromise due to gastric distention. During cardiopulmonary resuscitation (CPR), positive pressure ventilation may lead to gastric insufflation because of decreased pulmonary compliance and decreased lower esophageal sphincter tone. Essentially, gas delivered will follow the path of least resistance, which may be to the stomach. In our patient, gastric distention precluded effective ventilation and gastric decompression relieved ventilatory compromise. The values and pitfalls of clinical evaluation and capnography are presented.