It has been known that each component of the metabolic syndrome (MS) has an atherogenic potential and increases the risk of cardiovascular events. Therefore, patients who have MS are candidates for the development of atherosclerosis and accompanying complications. In this study, the authors assessed the levels of acute phase reactants as an indicator of inflammation in patients with MS. Twenty-five patients with recently diagnosed MS and not treated before who had at least 3 of 5 diagnostic criteria of MS listed in the Third Report of the Adult Treatment Panel National Cholesterol Education Program (NCEP-ATP III) guidelines were included in the study. Twenty healthy patients constituted the control group. Inflammatory parameters were compared between the groups. There was no significant difference between the MS and control group with regard to age and sex. White blood cell count (/mm(3)), high-sensitivity C-reactive protein (hs-CRP), uric acid, interleukin (IL) 6, and fibrinogen levels were found to be significantly higher in the MS group. Number of MS components was strongly correlated with serum levels of hs-CRP (r=0.688, P=.0001), IL-6 (r=0.546, P=.0001), fibrinogen (r=0.551, P=.0001), uric acid (r=0.517, P=.0001), and leucocyte count (/mmr3) (r=0.456, P=.002). Inflammation plays an important role in atherosclerotic complications, which is activated in MS. Increased number of MS components are strongly associated with elevated inflammatory and metabolic markers. Measurement of serum inflammatory parameters in patients with MS may be beneficial in detection and management of cardiovascular events and in the assessment of efficacy of treatment. J Clin Hypertens (Greenwich). 2010;12:136-144. (C)2009 Wiley Periodicals, Inc.