The aim of this work is a comparative assessment of the effect upon circulatory system of three antidepressant drugs with different mechanism of action. The study included 90 patients aged 60-78 (58 female, 32 male) with moderate to severe major depression in the course of unipolar or bipolar affective illness according to DSM-IV criteria. Clinical effects of all antidepressant drugs studied were similar but they differed in their action on cardiovascular system. During treatment with imipramine, significant changes of ECG, blood pressure, heart rate and tendency to pathologic orthostatic reactions were found. Similar changes although less intense were observed during doxepin therapy. During treatment with mianserin no statistically significant changes of blood pressure, ECG and orthostatic reaction were noted. Our results confirm that mianserin is well tolerated in elderly patients with depression and its clinical efficacy is comparable with imipramine and doxepin without side effects upon circulatory system.