Inflammation has been hypothesized to play a role in the development of hypertension. The high-sensitivity C-reactive protein (hs-CRP) is a well-studied marker of systemic inflammation that has a predictive power with regard to the development of hypertension. This study was designed to test the hypothesis that hs-CRP plasma levels are altered in hypertension. Moreover, the study was to assess whether chronic antihypertensive treatment with doxazosin would normalize hs-CRP and nitrites/nitrates. We measured plasma levels of hs-CRP and nitrites/nitrates in 44 normotensive subjects and in 44 patients with hypertension before and after doxazosin therapy for 4 months. hs-CRP plasma levels were significantly higher (P < 0.007) in untreated hypertensive group compared to controls. Significant decrease was observed for hs-CRP (P < 0.05) in hypertensive patients after antihypertensive treatment. Nitrites/nitrates were significantly lower (P < 0.0001) in the untreated hypertensive group compared to controls. A significant increase was observed for nitrites/nitrates (P < 0.05) in hypertensive patients after antihypertensive treatment. These results suggest that doxazosin treatment exerts anti-inflammatory effects in addition to its antihypertensive properties in hypertensive patients.