Background: Preeclampsia (PE) is a major cause of maternal and fetal morbidity and mortality in pregnancy. The aim of this work was to assess whether mean platelet volume and platelet distribution width during pregnancy could be used as markers for prediction of development of preeclampsia. Methods: A prospective cohort study was carried out to assess the probability of development of preeclampsia ≥13week with changes in platelet volume and distribution width in pregnant women, at maternity unit of obstetric and gynecology department, Zagazig University hospitals during the period from May 2017 till February 2018. 40 Pregnant women ≥13 week of gestation were invited to participate; 40 women accepted. At their 1st antenatal care visit, complete blood count test was taken for measurement of platelet volume (MPV), platelet distribution width (PDW), blood pressure was measured as well as urine albumin test by urinary dipstick was taken. Results: The correlation between high MPV and development of pre-eclampsia was highly significant; it showed a high specificity of 86.7% and a sensitivity of 100% with a p < 0.0001, the correlation between high PDW and development of pre-eclampsia was highly significant and the cut-off value of MPV was 9.2 fl and above and PDW was above 17.7, it showed a high specificity of 93.3% and a sensitivity of 96% with a p < 0.0001. Conclusions: Among platelet indices, the PDW are higher in pregnant women who developed later preeclampsia. Therefore, MPV& PDW measurement may contribute significantly in the identification of at-risk women.