Background; Events associated with a risk of death are the most serious complications of pharmacotherapy; One of these complications is prolongation of the QT interval leading to Torsades de Pointes, a life-threatening condition that can result in asystole and sudden death. Factors contributing to the development of the long QT syndrome include heredity, structural abnormalities of the heart, electrolyte disorders, female gender, advanced age, use of drugs with certain electrophysiological properties, and drug-drug interactions. Consideration of all these factors can help achieve the most accurate and objective assessment of the risk of these rhythm disturbances. Aims to assess the risk of prolongation of the QT interval and the development of Torsades de Pointes in psychiatric inpatients. Methods. The study enrolled 500 patients who received medical care in a psychiatric inpatient setting. The risk of QT interval prolongation and development of Torsades de Pointes was assessed using the MedSafety Scan medical decision support system. Results. Of the 500 patients treated in the psychiatric inpatient setting, 224 had a risk of QT interval prolongation and developing Torsades de Pointes; the incidence was highest in the group of elderly patients. The mean risk score was 7.59 3.29 in general, 6.02 3.14 in patients aged under 65 years, and 9.16 2.62 in subjects over 65 years of age. An analysis of the frequencies of risk factors for prolongation of the QT interval and Torsades de Pointes revealed that patients aged over 65 years most commonly had atrial fibrillation, chronic heart failure, heart valve disorders, hypertension, and a history of myocardial infarction. Patients under 65 years of age more commonly received medicinal products prolonging the QT interval and drug combinations that can lead to potential drug-drug interactions of relevant clinical significance. Conclusion. The obtained results indicate the importance of assessing the risk of QT interval prolongation and development of Torsades de Pointes in psychiatric inpatients as an affordable preventive tool that can increase the safety of drug therapy.