The aim – to determine the effectiveness of melatonin course therapy in a complex withthe main treatment on the dynamics of the daily arterial pressure (AP)profile and lifequality (LQ) in patients with arterial hypertension combined with osteoarthrosis (OA).Material and methods. In accordance with the purpose and objectives of our study, 130people in all, of different age and gender with hypertension and OA were examined.60 patients out of 130 people, divided into two groups, had AH combined with OA.Group I consisted of 30 patients with hypertension combined with OA, who receivedmelatonin in addition to the main treatment for a month. 30 patients, suffering fromcomorbid diseases hypertension and OA, who did not receive melatonin in their usualtreatment, constituted group II. Hypertention without concomitant OA was observedin 30 patients who were in group III. Group IV included 30 people with OA withoutconcomitant hypertension. The control group consisted of 10 practically healthy people.According to the research program, all patients underwent daily arterial pressuremonitoring (DAPM). Besides, the people under study were questioned to elucidate theirlife quality, using the international questionnaire SF-36.Results. The results obtained, indicate a tendency to normalize the daily profile inpatients of both groups: daily SAP decreased 9,57% in group I against 4,73% ingroup II, daily SAP 8,20% approached the target levels in group I against 2,96% ingroup II, SAP during the night monitoring period decreased 9,16% against 3,83% ingroup II. Daily DAP decreased 10,8% for patients of group I and 4,44% in group II,respectively, DAP in the active monitoring period decreased 9,57% in group I and5,29% in group II, at night monitoring period DAP was 9,87% lower in group I and5,91% lower in group II in comparison with the baseline before treatment. However,it should be noted that the results in group I are significantly better than in group II,especially during the night monitoring period, that indicates a better selection oftherapy in group I for patients with hypertension combined with OA.Conclusion. Melatonin (3 mg once daily at bedtime) as a component of complextherapy of hypertension combined with OA, facilitates the course of these diseases inpatients and improves their quality of life due to cardioprotective, antihypertensive andchondroprotective effects.