Objectives: Estimation of plasma mitochondrial DNA (mtDNA) levels in primigravida during 1st trimester and evaluation of its relation to development and severity of preeclampsia (PE). Patients & Methods: The study included 44 PE women (PE group) and 10 women free pf PE (Control group). At the 1st visit, all women underwent complete clinical examination and gave fasting blood sample for investigations. All women were asked to attend 4-weekly till delivery for evaluation of PE manifestations including increased systolic (SBP) and diastolic blood pressure (DBP) with proteinuria. SBP ≥160 mmHg and DBP ≥110 with proteinuria >2+ indicates severe PE and early-onset PE was diagnosed if manifestations appeared at <34 gestational weeks. Plasma levels of mtDNA were estimated using real-time PCR. Results: Seventeen women developed early-onset PE and 35 women had mild PE. Mean plasma levels of mtDNA were significantly higher in PE women than controls, in women developed early-onset PE than women developed late-onset PE and in women developed severe PE than those developed mild PE. Statistical analyses defined high 1st trimester plasma mtDNA as significant early predictor for development of PE and when combined with high SBP during 1st trimester as significant early predictor for severe PE. However, high plasma mtDNA during 1st trimester in young women as significant early predictor for development of early-onset PE Conclusion: High 1st trimester plasma level of mtDNA could be considered as a measure for mitochondrial dysfunction with subsequent liability to develop PE especially the early-onset type and severe manifestations.