Background. Despite the sufficient amount of data characterizings quality of life in adult patients with arterial hypertension and high-normal blood pressure, there is little information concerning the pediatric population. Objectives. The aim of the presented study was to investigate the association between health-related quality of life (HRQoL) parameters and the amount of increasing arterial blood pressure in children with primary arterial hypertension (PH) and high-normal blood pressure. Material and methods. We performed a case-control study with an assessment of the impact of BP elevation on HRQoL scores obtained in children 9-17 years old. BP was measured by ambulatory blood pressure monitoring (ABPM). HRQoL was assessed with the PedsQL survey. Results. The study included 179 participants. Analysis of the impact of high-normal BP or PH on HRQoL parameters found non-linear associations between BP and HRQoL. We found decreased quality of life indicators in children with high-normal BP and first stage PH. The HRQoL parameters of children with stable PH did not differ from those of the control group, with the exception of children with daytime systolic BP higher than 160 mm Hg, according to the ABPM data. Conclusions. BP elevation affects quality of life in children with high-normal BP and PH. This relationship is non-linear and consists of the fact that at the beginning of PH formation (systolic BP less than 130 mm Hg), HRQoL parameters are reduced. As BP becomes constantly elevated (systolic BP of 130-160 mm Hg), the HRQoL parameters improve. In children with severe grades of BP elevation, quality of life is low due to adaptation failure.