In recent years, data on the possibility of rapid clinical improvement after administration of ketamine in patients diagnosed with depression have been published more frequently. Ketamine, used as an anaesthetic during ECT procedures, despite earlier concerns, has both: a good safety profile and minimal effect on seizure threshold, which is used in cases of non-response to ECT. Postulated action of ketamine causes a rapid resolution of depressive symptoms raised hopes to accelerate therapeutic effect of ECT in patients with severe depression, but studies provide contradictory data pointing to brevity of the observed effect. Studies examining the use of ketamine combined with other anaesthetic drugs emphasized not only its antidepressant effect, but also improvement in hemodynamic parameters during ECT treatment. The aim of this work on one hand is to make psychiatrists aware that the role of anaesthesiologist at ECT is not limited to anaesthetise a patient and provide muscle relaxation, and, on the other hand, to make anaesthesiologists aware that drugs they use have a significant effect on seizure parameters and indirectly on the effectiveness of ECT. Due to small size of studied populations the issue of antidepressant efficacy of ketamine requires further exploration.