Clinical practice has been recently applied new approaches to classifying patients with arterial hypertension (AH), which are based on the determination of the summary risk suggesting the prognosis of the disease. This approach is quite efficient due to the fact that it takes into account a combination of the comparable clinical symptoms of AH, which characterize its course. The paper presents data on the values of blood pressure (BP) in AH and on daily BP profiles (DBPP) in 494 patients with different categories of a risk and on their endothelial function. It also gives the results of achievement of target BP levels in patients with AH having different categories of a risk during long-term (36-month) treatment with enapril and perindopril, as well as data on its impact on endothelial vasomotor function. The findings suggest that the higher the risk is, the more severe the hypertensive syndrome is; that the redistribution of DBPP occurs towards prognostically poor types and endothelial dysfunction (EDF) progresses. Treatment with angiotensin-converting enzyme (ACE) inhibitors results not only to the achievement of target BP levels and to the normalization of DBPP, but also to the amelioration of EDF. Moreover, the co-administration of ACE inhibitors and isosorbide-5-mononitrates causes additional antiischemic effects.