Our aim was to compare changes of vascular and metabolic parameters in patients with essential hypertension on treatment with combination of perindopril with either indapamide retard or hydrochlorothiazide.The study involved 40 patients who were randomly assigned to perindopril 5-10 mg/day in combination with indapamide retard (P+I) 1.5 mg/day (n = 20) or with hydrochlorothiazide (P+HT) 25 mg/day (n=20). Waist circumference, body mass index, blood lipids and glucose, endothelial function (EF) determined as the change of resistance index after inhalation of salbutamol, arterial stiffness measured as mean pulse wave velocity after sublingual trinitroglycerin (PWVtng) were evaluated at baseline and 6 months thereafter. Vascular responses were calculated from digital pulse waves registered using photoplethysmography.Dynamics of BP after 6 months did not differ significantly between groups. Treatment with combination of P+HT resulted in significant decrease of EF (-24,3%, p<0,05) accompanied by negative changes of triglycerides (+13,4%, p<0,05) and glucose levels (+9,8%, p<0,05), whereas combination of P+I did not affect endothelial function and was metabolically neutral. PWVtng significantly decreases on both regiments of treatment with the trend in favor of P+I combination (-13,4%, p<0,001 versus -9,8%, p<0,01 for P+I and P+HT combinations, respectively).Thus, despite the similar BP reduction the combination of ACE-inhibitor--perindopril with indapamide retard possesses more favorable vascular and metabolic effects compared to combination with hydrochlorothiazide that potentially may account for different prognosis of patients with arterial hypertension on long-term treatment.