A 67-year-old man was found to have massive pituitary necrosis occupying approximately 85% of the anterior lobe after being supported with mechanical ventilation for 35 days. The findings were compatible with "respirator pituitary" found in mechanically ventilated patients. The lesions represent coagulative infarctions due to ischemia. The role of the respirator is believed to be buying time to allow the changes to develop.