Propafenone is a type 1c antiarrhythmic drug that recently has become available for clinical trials within the United States. We present the case of a 2-year-old child who accidentally ingested 1,800 mg (133 mg/kg) of propafenone. The patient subsequently developed cardiac conduction abnormalities and generalized seizures. Following the administration of IV phenytoin, cardiopulmonary collapse occurred. The patient had a successful outcome with aggressive cardiopulmonary life support.