Serum high sensitivity C - reactive protein and systemic hypertension Inflammation has been shown to be correlate with endothelial dysfunction and relate to rennin angiotensin system. This study is a case control analytic study that was conducted in El-Kasr El-Aini Hospital in order to find out the relation between high sensitivity-CRP and hypertension, the study included 60 patients with primary hypertension and 15 normal subjects as a control group.Exclusion criteria: Secondary hypertension. Infection, autoimmune, inflammatory disorders, malignant disease and steroid therapy. Renal or hepatic impairment.All patients included in the study were subjected to the following:Full history taking with special emphasis on history of hypertension, drug therapy, complications of hypertension and cardiac history ,full medical examination including blood pressure, body mass index and signs of inflammation and autoimmune disease, Laboratory investigations including: complete blood count, erythrocyte sedimentation rate by wintergreen method, Fasting and 2 hours post-prandial blood sugar level, urea, creatinine, uric acid, SGPT, SGOT, PT, Cholesterol, Triglycerides, HDL and LDL,Serum level of C-reactive protein by a high sensitivity assay method ,ECG..