Aim. To assess vascular reactivity and endothelial function (EF) in people with workplace hypertension (WPH) and arterial hypertension (AH) patients.Material and methods. Fifty men with Stage I-II AH were examined, including 30 with WPH, according to 24- hour blood pressure monitoring (BPM) during workdays and weekends (20 subjects with low workplace stress levels). Mean age of the participants was 42,8±8,2 years. Cold stress test, psycho-mental reading test, and arithmetic counting (AC) test were performed. Healthy controls were 30 males (mean age 40,6±7,1 years). Endothelium- dependent vasodilatation (EDVD) was assessed during the cuff test.Results. BP reaction during stress tests was similar in all patients. During AC test, WPH patients demonstrated greater systolic blood pressure (SBP) increase than controls and AH patients. Increased cardiovascular reactivity during cold stress test was associated with AH in family history. In WPH subjects, EDVD was lower than in AH patients, and brachial artery occlusion was associated with vasoconstriction in 50%. Patients with cuff test vasoconstriction had lower SBP increase in cold stress test and greater SBP increase during reading test; diastolic BP (DBP) increase was greater in AC test. There was a negative correlation between DBP increase during AC test and EDVD. Conclusion. WPH patients differed from AH patients in terms of increased stress reactivity, associated with EF. Participants with cuff test vasoconstriction demonstrated vascular reactivity different from that in other AH patients