Backgrounds A few studies suggested that ginseng, a widely recognized herbal drug, might elevate blood pressure(BP) but, the issue remains controversial. In contrast, some investigators have emphasized the protective effects of ginseng from vascular injuries. We sought to determine the effect of Korea red ginseng on BP and inflammatory markers in hypertensive patients. Methods A single center, 12-week, randomized, placebo-controlled, double-blinded study was performed in 135(73 males, age 56짹8) treated hypertensive patients. All subjects were divided into 3 groups: Placebo(n=45), Ginseng 1.5g (n=45), Ginseng 3.0g(n=45). The primary endpoint was the observation of BP changes before and after ginseng intake assessed with office, central (SphygmaCorMx, AtCor Korea) and 24hr ambulatory BP measurements. The secondary endpoint included the change of inflammatory markers, anti-oxidative markers, indices of insulin resistance. Results There was no significant BP elevation in all BP parameters. We found a tendency for reduction in office and central BP after ginseng intake compared with placebo. Moreover, there was a significant reduction of 24 hr ambulatory BP, especially the nocturnal BP, which wasn���t dose-dependent. Additionally, there were tendencies for improvement in inflammatory markers such as TNF-a and insulin resistance. Conclusions We could suggest that the Korea red ginseng had no harmful effect on BP control in treated hypertensive patients. In addition, anti-inflammatory effects could be expected.