A woman with acute poisoning from extended-release paracetamol presented at 14.5 hours post-ingestion. The paracetamol’s absorption phase and elimination half-life appeared prolonged, with peak blood concentration occurring at 20 hours post-ingestion, requiring an extended course of intravenous N-acetylcysteine. Current treatment recommendations, based on experience with a different formulation in the United States, may not be appropriate for the Australian formulation.