Objective: The predictive role of neutrophil-to-lymphocyte ratio (NLR) for preeclampsia (PE) has been explored in several studies and current evidence seems to be conflicting. The aim of this study is to compare the NLR values of mild and severe preeclampsia with the normotensive pregnant women, in order to explore the predictive role of NLR for preeclampsia and whether the NLR value has significant difference between severe and mild preeclampsia. Design and methods: We systematically searched Pubmed, Embase, Web of Science and Cochrane database for relative literature up to May 2019. The statistical analysis was performed using Stata 12.0 software. Results: Totally 15 eligible studies consisting of 3982 patients were enrolled in our meta-analysis. The NLR value is higher in preeclampsia when compared to healthy pregnant women (3270 women, MD: 1.44, 95% CI [1.04, 1.83]). Furthermore, NLR value is higher in severe preeclampsia than in mild preeclampsia (1287 women, MD: 1.12, 95% CI [0.69,1.56]). Conclusions: The findings of our meta-analysis suggest that NLR value is higher in preeclampsia patients especially in severe preeclampsia. The NLR might be a useful laboratory marker for clinical prediction and disease severity evaluation of preeclampsia. However, given that the available evidence is mainly drawn from casecontrol studies, future cohorts are needed in this field to accurately determine optimal timing and cut-off values that may be used in the clinical setting.