Antipsychotics and antidepressants are widely used in clinical practice for treatment of mental disorders. In comparison to general population patients diagnosed with schizophrenia and depression are at higher risk for developing some of cardiovascular adverse effects related to prescribed therapy. Adverse effects after antipsychotics and antidepressants treatment may vary in clinical presentation, starting from asymptomatic ECG changes to serious arrhythmia and in some cases sudden cardiac death. One of the most common reported adverse effects regarding both antipsychotics and antidepressants is orthostatic hypotension. In addition, QT prolongation has been reported as a ECG finding associated with ventricular arrhythmia such as torsade de pointes. Even though, not that frequent, torsade de pointes has potential to evolve in lethal arrhythmia leading to sudden cardiac death. Fatal outcome of antipsychotic and antidepressant medication has been reported in some cases, presented with myocarditis and cardiomyopathy at pathological basis. Underlying pathophysiological mechanisms od antipsychotics and antidepressants induced cardiotoxicity are mediated by different ion channel blockade, adrenergic and muscarinic receptor blockade. Prolonged QT interval is associated with HERG potassium channel blockade. This inhibition affect physiological repolarization of cardiomyocytes leading to action potential prolongation, manifested on ECG as QT prolongation. Aimed to prevent cardiovascular adverse effects during treatment of mental disorders special attention should be given on preventive cardiac function monitoring, especially in subjects with cardiovascular comorbidities.