Aim: this study to compare the density of decidual natural killer cells (CD56) in deciduas of placental bed in patients with Intrauterine Growth Retardation (IUGR) and women with normal pregnancy. Patients and Methods: in the study 23 pregnant women were recruited and divided into 2 groups: The study group (A): included 14 patient females which diagnosed as IUGR by ultrasound of the third trimester and the control group (B): included 14 normal females at third trimester with no antenatal complications recruited from the antenatal care clinics. All patients underwent elective cesarean delivery. Decidual biopsies were taken during the operation. An immunohistochemical staining for decidual natural killer cells (dNK, CD56+^bright) and a semi quantitative scoring were done. Results: In this study it was found that the Immunohistochemical scores and dNK cell population density is statistically higher in controls compare with IUGR group (P<0.01) Conclusions: findings reinforce the concept of pregnancy as a controlled systemic inflammatory state that if altered can have adverse consequences for the mother and the fetus.