Objective. The purpose of the work is to use a meta-analysis to investigate the effect of melatonin monotherapy on the hemodynamic parameters of normotensive and hypertensive rats.Design and methods. For our metaanalysis, we selected 39 publications, of which 28 studied the effect of melatonin monotherapy on hemodynamic parameters in normotensive rats, 12 in SHR rats, 7 in rats with fructose-induced hypertension, 3 in rats with L-NAME-induced hypertension. Meta-analysis of study results was conducted using the statistical program Review Manager 5.3 (Cochrane Library).Results. Our meta-analysis showed that melatonin has a dose-dependent hypotensive and bradycardic effect with a single intravenous administration. The hypotensive effect of chronic administration of melatonin will increase with the duration of therapy. Moreover, the hypotensive effect of melatonin is significantly higher in hypertensive animals compared to normotensive ones. Long-term therapy with melatonin reduced blood pressure levels in normotensive animals by no more than 2 mm Hg, and in hypertensive rats by an average of 20–30 mm Hg.Conclusions. As a result, since melatonin demonstrates a good hypotensive effect in various models of experimental hypertension, it is advisable to continue clinical studies of the possibility of using melatonin in the treatment of hypertension, which should focus on monotherapy, dose selection, various methods of increasing bioavailability and prolonging the effect.