Preeclampsia is characterized by new-onset hypertension, proteinuria and is responsible for substantial maternal and fetal morbidity. The electrolytes like sodium, potassium and chloride contribute significantly in the functioning of the vascular smooth muscles and may play an important role in the aetiopathogenesis of hypertension. The present study was undertaken to evaluate the role of serum ionized sodium, potassium and chloride levels as a predisposing factor in the genesis of preeclampsia and to find out the association of these elements with blood pressure in preeclamptic pregnant women living in Riyadh, Saudi Arabia. One hundred and twenty subjects were enrolled in this case-controlled study and divided into three groups; control, highrisk of preeclampsia (HR) and preeclampsia (PET) of 40 each. Blood samples were obtained from all the patients and the serum levels of sodium, potassium and chloride were determined. Statistical analysis was performed by one way ANOVA and Pearson’s correlation coefficient. In preeclamptic group, the mean values of Na+, K+ and Cl- were 138.27±2.99, 3.56 ± 0.38 and 104.2 ± 3.86 mEq/L respectively in comparison to control (135.44 ± 2.24, 4.11 ± 0.42 and 100.4± 2.43 mEq/L respectively). Raised levels of Na+ and Cl- in preeclamptic patients was significant at p<0.001 level of significance. There was significant positive correlation between raised sodium levels and systolic blood pressure (P<0.05), while K+ showed a significant negative association with increased diastolic blood pressure. On the other hand, chloride exhibited insignificant correlation with blood pressure. In conclusion, our study suggests that hypernatremia and hypokalemia observed in preeclamptic patients bring about altered homeostatis of these elements in serum and therefore may act as predisposing factors in pathogenesis of preeclampsia.