Cardioversion used for the treatment of various cardiac arrhythmias is a safe and effective procedure with infrequent complication. The restoration of sinus rhythm is followed by a improvement in hemodynamics, but acute pulmonary edema has been reported as a rare complication following successful electrical reversion of various tachyarrhythmia to normal sinus rhythm. This report describes a 42-year-old woman with a history of schizophrenia who experienced pulmonary edema after cardioversion for torsade de pointes. She had taken chlorpromazine and haloperidol for schizophrenia. The antipsychotic drugs were suspected to induce QT interval prolongation and resultant torsade de pointes. Two hours after cardioversion, pulmonary edema developed on chest X-ray and chest computed tomography. She responded to conservative treatment including oxygen therapy and the pulmonary edema improved on the second hospital day. The mechanism of pulmonary edema after cardioversion is still uncertain and remains controversial.