Preeclampsia is a pregnancy-specific disease with the increased risk of maternal morbidity and mortality. It is characterised by placental vascular dysfunction. Despite the numerous studies on preeclampsia, studies evaluating proliferation of villous trophoblasts in preeclamptic placentas are limited. Ki67 is a proliferation marker that expresses in the nuclei of proliferating cells. In this study, we examined the proliferation of villous trophoblasts in placentas of preeclamptic patients by using Ki67 and compared it with placentas of normal pregnant patients.