Electroconvulsive therapy has been a procedure used in the field of psychiatry since the first half of the last century. Over the years, the method of its application has been modified, and today the ECT procedure is carried out around the world according to international guidelines. The mechanism of action of ECT is still not fully understood. We are familiar with numerous biological theories that explain the therapeutic effect of ECT. They can be divided into three large groups; neurophysiological hypotheses, neurobiochemical hypotheses, and the neuroplastic hypothesis. ECT has antidepressant, antipsychotic, anticatatonic, and antiparkinsonic effects. Indications for ECT are severe depressive episode with suicidality, severe episodes of depression and mania within bipolar affective disorder (BAP) with suicidality/agitation, manic delirium, catatonia, malignant neuroleptic syndrome, postpartum depression, therapeutically resistant mood disorders and treatment-resistant schizophrenia. The protocol for the application of ECT is very safe today, the risk of severe complications is minimal. However, when applying ECT, care should be taken in patients with somatic disorders. The side effects of this therapy can be somatic and cognitive. From somatic headaches, nausea and vomiting most often occur, and from cognitive ones, confusion is most often present. Today, ECT is used in short-acting intravenous anesthesia. The goal is to induce convulsions lasting an average of 30 to 60 seconds. Bilaterally positioned electrodes are the gold standard in the ECT application.