Preeclampsia is a pregnancy specific multisystemic syndrome and a leading cause of maternal and fetal morbidity and mortality. The study comprised of 30 normal and 30 preeclampsia cases in their third trimester of pregnancy and the following estimations were done: Serum and urine uric acid, plasma nitric oxide (NO), urine pH, urine creatinine. There was an increase in both serum and urine uric acid levels in the cases (P = 0.000), though the urinary pH in both the groups were similar (P = 0.4). Urinary creatinine in both groups was not different. Plasma nitric oxide in the preeclampsia cases was significantly low (P = 0.000) as compared to controls. It was about one third the levels obtained in controls. There was a negative correlation of systolic BP with plasma NO levels in controls and positive in cases. As pregnancy progressed there was a decrease in plasma NO levels in both cases and controls. Urine uric acid to creatinine ratio increased with the decrease in NO levels and can be used as a marker for preeclampsia.