A 63-year-old woman presented with drowsy consciousness and dyspnea, followed by respiratory failure, after taking a bottle of parathion for suicide. 2. Sinus tachycardia was noted initially by ECG and Q-T interval prolongation with pleomorphic ventricular tachyarrhythmia ('Torsade de pointes') occurred on the third day of admission. 3. Torsade de pointes was relieved by magnesium sulfate and atropine sulfate intravenously. Q-T interval returned to normal on the fifth day of admission. 4. Practicing physicians should be aware of this uncommon type of cardiac toxicity caused by organophosphate poisoning, Q-T interval prolongation and pleomorphic ventricular tachyarrhythmia.