Objective: Preeclampsia is a major cause of maternal and fetal mortality worldwide. A reliable test that would identify the "at risk" group of pregnant women is not available. Homocysteine and ADMA have been shown to be elevated in disorders characterized by endothelial dysfunction including preeclampsia. Paraoxonase 1 is though to influence serum homocysteine and to play a role in preeclampsia. Aim and Study Design: In this study, we aimed to measure serum homocysteine and ADMA in mild (n=24) and sever (n=12) preeclampsia compared to normotensive pregnant women (n=38) and to evaluate their roles as markers to identify women at risk of developing the disease. We also investigated a possible association between PON1 55 and 192 polymorphisms and preeclampsia in Egyptian population. Results: Homocysteine and ADMA were significantly high in preeclampsia compared to normotensive pregnany. Both homocysteine and ADMA differed significantly between mild and sever preeclampsia. Follow-up of the normotensive pregnant women demonstrated a significant positive correlation between serum homocysteine and subsequent development of hypertension after the 36th weak of gestation. No association was observed between PON1 55/192 polymorphisms and preeclampsia. Conclusion: Our results suggest that homocysteine and ADMA may have a role in the pathogenesis of preeclampsia and could be regarded as markers for the severity of the disease. Hyperhomocysteinemia could predict women at risk of developing pregnancy-related hypertension. PON1 55/192 polymorphisms have no role in development of preeclampsia in Egyptian women.