Abstract Background: Preeclampsia remains a leading cause of maternal and perinatal morbidity and mortality worldwide. Lactate dehydrogenase (LDH), a cytoplasmic enzyme released during cellular damage, reflects endothelial dysfunction and tissue hypoxia. Elevated serum LDH levels may serve as a valuable biomarker for assessing disease severity and predicting adverse outcomes in preeclampsia. Objective: To evaluate maternal serum LDH levels as a biochemical marker of disease severity and assess its predictive value for fetomaternal outcomes in women with preeclampsia. Methods: This prospective observational study conducted at Mahadevappa Rampure Medical College, Kalaburgi, included 30 pregnant women diagnosed with preeclampsia admitted to the Department of Obstetrics and Gynecology. Serum LDH levels were measured within 24 hours of admission using standard enzymatic kinetic method. Patients were classified into mild (36.7%) and severe (63.3%) preeclampsia based on clinical and laboratory criteria. Maternal outcomes (eclampsia, HELLP syndrome, abruption placentae, ICU admission) and fetal outcomes (birth weight, Apgar scores, IUGR, NICU admission, perinatal mortality) were documented. ROC curve analysis determined optimal cutoff values for predicting adverse outcomes. Results: Mean serum LDH levels were significantly higher in severe preeclampsia (687.4±142.6 IU/L) compared to mild preeclampsia (412.3±68.5 IU/L; p<0.001). Strong positive correlations existed between LDH levels and blood pressure parameters (r=0.742-0.756, p<0.001). Women with LDH ≥600 IU/L experienced significantly higher rates of eclampsia (30.8% vs 0%, p=0.012), HELLP syndrome (38.5% vs 0%, p=0.004), and ICU admission (53.8% vs 5.9%, p=0.003). Neonates born to mothers with elevated LDH had lower birth weight (2.08±0.38 vs 2.64±0.42 kg, p<0.001), increased NICU admissions (92.3% vs 41.2%, p=0.003), and higher perinatal mortality (23.1% vs 0%, p=0.038). ROC analysis identified optimal cutoff values of 580 IU/L for severe preeclampsia (sensitivity 89.5%, specificity 90.9%) and 725 IU/L for perinatal mortality (sensitivity 100%, specificity 77.8%). Conclusion: Serum LDH is a reliable, cost-effective biochemical marker for predicting disease severity and adverse fetomaternal outcomes in preeclampsia. Routine LDH measurement enables early risk stratification, intensive monitoring, and timely intervention in high-risk pregnancies.