•Several evidence points that the dysfunction of endothelial L- arginine - nitric oxide system in pre- eclampsia we have investigated the influence of dietary supplementation with L- arginine on blood pressure •10 pre- eclamptic women on low sodium diet received orally 3 grams of L- arginine daily for 3 wks as a supplement to standard therapy. The difference in systolic blood pressure (SBP) Diastolic Blood pressure (DBF) and mean arterial pressure (MAP) were determined. •After 3 weeks of treatment, values of SBP, DBP and MAP were significantly lower in the group taking L- arginine .Also the requirement for anti-hypertensive drug was reduced.