A 32-year-old man developed dyskinesia, cardiac arrhythmia and partial seizure following paliperidone overdose.The man with a history of psychosis, presented with opisthotonus, muscular spasms, rigidity and tongue protrusion 20 hours after intentional ingestion of 168 mg of extended-release paliperidone. At presentation he was hypotensive and tachycardiac. His head was rigid and rotated and tongue clonus was noted. His electrocardiogram showed narrow complex tachycardia with possible atrioventricular block or atrial flutter. The QT interval was prolonged.The man's dystonic reaction completely resolved within few minutes following IV diazepam administration. His investigations showed glucose 119 mg/dL, creatinine 0.73 mg/dL, potassium 4.0 mMol/L, sodium 139 mMol/L, creatine kinase 92 U/L and serum ethanol was absent. After 3 hours his BP was 115/70 mmHg and heart rate was 70 beats/minute. His ECG revealed sinus rhythm with normal PQ and QT intervals. Nine hours after admission, he had partial seizure, which resolved after another diazepam administration. During hospitalisation he had mild sinus tachycardia for 10 days. He was discharged on day 22 in stable condition and normal vital signs. Author comment: "We report a case of paliperidone overdose in a patient with psychosis showing three [dyskinesia, cardiac arrhythmia and partial seizure] concomitant different clinical pictures." Villa A, et al. Dyskinesia, cardiac arrhythmia and partial seizure associated with paliperidone overdose: A case report. Italian Journal of Medicine 9: 373-376, No. 4, 2015. Available from: URL: http://doi.