A healthy 3-year-old boy presented to our emergency department with sudden onset of abnormal movement. This patient had been treated for 2 days with conventional doses of an antihistamine/decongestant cold preparation for upper respiratory infection symptoms. The child was confused and restless, with posturing of limbs. Cranial nerve function was intact. Gastric lavage yielded an aspirate the same color as the cold syrup the child had ingested. A diagnosis of dystonic reaction was made, and the child was treated with benztropine, which effected resolution of his symptoms. This is the first reported case in the literature of dystonia induced by an antihistamine and treated with benztropine.