Background: The study was designed to compare the serum leptin concentrations in pre-eclamptic pregnant women to that of normotensive pregnant women and to investigate the possibility of leptin being used as a marker of severity of pre – eclampsia. Methods: A cross–sectional study was carried out in 72 pre – eclamptic women (26 with mild pre–eclampsia and 46 with severe pre–eclampsia) and 72 pregnant normotensive controls, matched for age, parity (primiparity) and body weight, in the third trimester of pregnancy. Serum leptin levels were evaluated in all subjects using a human leptin ELISA test kit. Leptin levels were compared between the groups and correlated to mean arterial blood pressures, degree of protenuria and body mass index in both groups. Data was analyzed using Epi-Info 3.5.3 and SPSS 17.0