A case of successful suicide from overdose of amitriptyline, perphenazine & midazolam is described. Postmortem findings were inadequate to explain the death. Sudden cardiac arrest suggested that the death from overdose probably resulted from drug cardiotoxicity. The physicians should be aware of this serious complication when prescribing a combination of these potential lethal drugs. A limited supply should be given to a depressed patient. 10 refs.