Cocaine poisoning has increased recently, and survival is rare because of its sudden onset and rapidly fatal course. A patient is described in whom cocaine poisoning developed. This condition was manifest by the findings of acute agitation, diaphoresis, and tachycardia, and was complicated by grand mal seizures, severe respiratory and metabolic acidosis, apnea, and accelerated idioventricular rhythm. After control of the seizures with diazepam and treatment of the acidosis with ventilation and bicarbonate, the ventricular dysrhythmia abated, and the patient made a quick recovery. Recently reported experiments suggest that seizures are a major determinant of lethality in cocaine poisoning. Treatment of the seizures is of prime importance, and correction of the acidosis can normalize cardiac rhythm and function in these critically ill patients.