Objectives: We aimed to demonstrate cell-cell adhesion and apoptotic changes in preeclamptic placentas by examining the expression of CD44 and IL-10. Material and methods: Placenta samples of 15 preeclamptic and 15 healthy 35–38th week-pregnant women were involved in the study. Tissue samples were taken only from the maternal side of the placenta and fixed in 10% formaldehyde, then blocked in paraffin wax and 5 μm-thick sections were cut and stained with Masson Trichrome. Antigen retrieval was performed for sections, incubated with CD44 antibody and anti-IL-10 antibody. After the application of streptavidin peroxidase followed by AEC chromogen solution, sections were counterstained with Mayer hematoxylin. Results: In the preeclampsia group, increased CD44 positive expression was observed in maternal decidua cells and fibroblast cells close to root villi. CD44 was positively expressed in muscle cells around the blood vessels, mucosal connective tissue areas, syncytial nodes, and syncytial bridges. In the preeclampsia group, significant increased IL-10 expression was seen in subendothelial layers of the medium-sized vessels in the maternal region. IL-10 was also positively expressed in decidua cells outside the vessels, and inflamed connective tissue areas, chorionic villus cells with intense inflammation in intervillous spaces. Conclusions: CD44 was found to be an essential molecule in the regulation of vascular permeability, inflammatory response, activation of the cells, cell-to-cell interaction, and the signaling pathways to which they are associated. Since IL-10 regulates appropriate pregnancy outcomes and contributes to the balance of anti-inflammatory signals via both paracrine and autocrine regulators of trophoblast activity, we proposed that it might be a key to elucidate the etiology of preeclampsia with CD44 receptor.