The objective of this report is to describe an acidemic patient with one of the largest recorded acetaminophen ingestions in a patient with acidemia who was treated with supportive care and intravenous (IV) N-acetylcysteine. A 59-year-old female with a history of depression was found comatose. In the Emergency Department, she was obtunded with agonal respirations and immediately intubated. Activated charcoal was given through a nasogastric tube. An initial acetaminophen serum level was 1141 mg/L. The patient was started on IV N-acetylcysteine. The acetaminophen level peaked 2 hours later at 1193 mg/L. She was continued on the IV N-acetylcysteine protocol. The next day her aspartate aminotransferase was 3150 U/L, alanine aminotransferase was 2780 U/L, and creatinine phosphokinase was 16,197 U/L. There was no elevation in bilirubin or international normalized ratio (INR). Transaminase levels decreased on day 3 and normalized by day 4 when she was transferred to a psychiatric unit. Few cases have been reported of strikingly elevated acetaminophen levels in poisoned patients who did not receive hemodialysis. These patients did have increased lactate levels, and some had normal liver function tests. All of these patients received N-acetylcysteine and survived the poisoning without sequelae. This patient in this report was unique in that she had the highest reported serum acetaminophen level with acidosis and was treated successfully with only IV N-acetylcysteine and supportive care.