Background: Cerebral ischemia initiates an inflammatory response in the brain which is a composite process that involves many inflammatory mediators.The investigation of inflammatory response in the acute stage may contribute to improve the treatment of ischemic stroke. Objective: We assessed the relationship between peak values of serum interleukin-6 (IL-6), intercellular adhesion molecule-1 (ICAM-1),erythrocyte sedimentation rate (ESR), c-reactive protein (CRP)and nitric oxide (NO)in the first week after ischemic stroke, with measures of stroke severity and outcome.Methods:forty-five patients (22 males and 23 females) with ischemic stroke were prospectively recruited. Serum IL-6, and other markers of peripheral inflammation, was measured at time points 24 h, as well 7 days after symptom onset.Twenty-five age-matched volunteers were used as controls. We correlated levels with stroke severity assessed by the NIH Stroke Scale; stroke outcome at 1 month assessed by BI and computed tomography (CT) brain infarct volume. Result(s): Peak serum IL-6 and CRP concentrations correlated significantly (p < 0.001) with CT brain infarct volume (r = 0.75) and NIHSS at 1 week (r = 0.72). They correlated similarly with clinical outcome at 1 month. Strong associations were also noted between either peak serum ICAM-1 or NO concentrations and short-term stroke outcome. Conclusion(s):These data provide evidence that the peripheral inflammatory response may be related to the severity of acute ischemic stroke, and may be used as predictors for clinical outcome.