Amniotic fluid (AF) is essential for fetal development and maturation during pregnancy. The levels of proteins in AF have been determined in many studies to screen for potential biomarkers of pregnancy-associated abnormalities. Alpha-fetoprotein (AFP) is a major AF and plasma protein produced by the yolk sac and the liver during the fetal period. APF serum concentrations are commonly used for screening of many syndromes. Electromagnetic fields (EMFs) were reported to change gene expression in the embryo and in adults. The aim of this research was to assess the effects of 50hertz/1millitesla EMFs on AFP expression in the AF in the mouse embryo. AF samples were obtained from pregnant mice in gestational days 16 and 18. AFP relative expression was studied by western blotting. The results of this study showed that AFP relative expression increases in the EMF-treated AF as compared with either SHAM or control groups. It is concluded that EMF increases the AFP relative expression in the AF. It is also suggested that EMF may change the AFP expression in the AF by altering the expression of genes, including AFP, and/or by affecting the permeability of blood barriers.