One month following carbon monoxide poisoning, a 39 year-old man developed incontinence, memory impairment, disorientation and emotional instability. He was hospitalized 7weeks later, and during hospitalization he exhibited myoclonic movements of the neck and lower limbs. He was given piracetam intravenously for 11 days. The myoclonus was significantly reduced by the third day of treatment and had disappeared by the seventh day. There was no recurrence following cessation of treatment.