Transdermal scopolamine (Transderm-Scop) is being increasingly used for effective prophylaxis of motion sickness. It is reported to have a lower incidence of CNS side effects than orally administered scopolamine. Although uncommon, such side effects occur more often in the elderly, in those with preexisting psychiatric disease, and in patients concurrently taking other medications with anticholinergic activity. Correct diagnosis may be delayed by the occult location of the delivery system, delayed onset of symptoms, prolonged action, absence of peripheral manifestations, and negative toxicologic screening tests. Treatment is usually supportive. Physostigmine should be reserved for the treatment of severe symptoms.