Despite improved prognosis, patients with systemic Lupus, remain at increased risk of early vascular events due to premature atherosclerosis. We assessed the endothelial dysfunction in SLE as a marker of early atherosclerosis. In thirty seven (37) female patient endothelial dependant vasodilatation (EDD) was assessed at the brachial artery in response to shear stress and glyceril trinitrate administration (NMD), intimae media thickness of the common carotid artery was also measured using high resolution B-Mode ultrasonography., anticardolipin antibodies (done only in 18 patients) Lipid profiles, ANA were also assessed. No statistically significant difference between patients and control in basal FMD (D-1) (P=0.5) or percent change in flow mediated dilation (D-2) P = 0.3 and no change in NMD (P = 0.2). There was weak but statistically significant correlation between FMD% and NMD% (r = 0.3, P = 0.05). Despite the disease activity according to SLEDAI (where 45.9% of patients were severely active) there was no correlation between either disease activity and FMD (r =0.03, P = 0.8), or disease duration (2.4 +/- 3.3 years) (r = 0.7, P = 0.8) Weak but statistically significant negative correlation between hypercholesterolemia and endothelial dysfunction (r = 0.3, P = 0.05). We tried to find differences between patients themselves dividing them into those with FMD <10% (n = 23 patient, 62.2%) FMD >= 10% (n = 14 patient, 37.8%) or FMD %/ NMD % < 0.7 (n = 23 patient, 62%), FMD % /NMD> 0.7 (n = 14 patient, 38%). However no significant differences between them as regard clinical and laboratory data. In conclusion, FMD was not different between patients and control thus its use as a predictor of future cardiovascular events is questionable. [Aysha I.Z. Badawi, Randa F Abd Al Salam, Amal A El Wahab. Endothelial Dysfunction In Systemic Lupus Erythermatosus. Life Science Journal 2010;7(4):98-104]. (ISSN: 1097-8135).