To the Editor: A 42-year-old man with depression overdosed on acetaminophen 37.5g and was admitted to our hospital. He had been taking flunitrazepam 12 mg, etizolam 5 mg, clotiazepam 15 mg, lormetazepam 6 mg, every day for over a year. He was diagnosed with acetaminophen intoxication and benzodiazepine (BZD) withdrawal. Gastric lavage was carried out, and N-acetylcysteine was administered, with mild hepatic dysfunction. Because his delirium did not improve, he was admitted to the psychiatric ward on Day 5. Although his delirium became aggravated after an attack of grand mal convulsions on Day 6, his delirium completely disappeared on Day 10. Electroencephalographic examination (EEG) on Day 12 was normal; hepatic dysfunction had also improved upon biochemical testing carried out on Day 14, with no observation of other abnormalities, and discharge from the hospital was planned. However, disorientation and visual hallucinations were observed from Day 18, with no contributing factors, and the patient returned to a state of delirium state once again. No abnormalities were observed on the head CT scan and blood/biochemical testing on Day 20. Slowing of brain waves was observed on EEG compared with that of Day 12. Subsequently, although his delirium continued for over 2 weeks, the delirium completely disappeared on Day 40, and slowing of brainwaves was improved upon EEG. The delirium did not recur after then, and the patient left the hospital.