Human placenta produces a wide variety of specific proteins, One of them is pregnancy–associated plasma protein A (PAPP–A). The aim of this study was comparison of serum level of PAPP–A in third trimester of normal pregnancy without preeclampsia and pregnancy with preeclampsia. In this study, 250 normal pregnant females without preeclampsia and 250 cases of preeclampsia were evaluated. They were compared for serum PAPP–A. The mean age was not statistically different between two groups (p=0.2564). Preeclamptic pregnant females showed a non–significant relationship in serum PAPP–A levels when the results were compared with normal pregnant females without preeclampsia.