The case of a 2 1/2-year-old comatose white boy successfully treated for acute phencyclidine poisoning has been reported with a brief review of symptoms and therapy. Supportive treatment consisted of maintaining intravascular volume; giving diuretics as needed to insure an adequate urinary output; controlling excessive secretions and seizure activity; and providing respiratory support. The patient recovered over a ten-day period of treatment without neurologic or psychologic sequelae.