Oleic acid and oleate are pulmonary toxins used to create laboratory models of acute respiratory distress syndrome, but there is little information on human toxicity. We report the intentional ingestion of 50 mL sodium oleate 20% by a 22-year-old woman with no symptoms for the first 2 days after ingestion. Her respiratory status deteriorated rapidly on day 3 progressing to acute respiratory distress syndrome (PaO2/FIO2 < 100 mm Hg) on day 4. Treatment with high-dose steroids and intensive respiratory support including high-frequency jet ventilation were associated with gradual but complete recovery by day 39. The delayed onset of symptoms suggested that the lung injury was due to the systemic circulation of oleate to the lungs rather than to direct aspiration. In oral poisoning by sodium oleate, the lung is the first and most lethally affected target organ in humans. This case demonstrates that ingestion of a relatively small amount of sodium oleate can cause delayed, progressively severe, lung injury.