Intra-uterine growth restriction (IUGR) is an important perinatal problem giving rise to increased morbidity and mortality in the growth restricted fetus. The aim of fetal medicine today, is to prevent the mere occurrence of IUGR in high risk pregnancies and to deliver the fetuses already afflicted with growth restriction, before they have suffered from the effects of hypoxia. The use of Doppler provides this information, which is not readily obtained from the other conventional tests of fetal well being. The Doppler patterns follow a longitudinal trend in the arterial and venous circulation of the fetus as well as the placental vasculature guiding management decisions regarding the appropriate time of delivery. Progressive knowledge of the fetal circulation and its adaptation when the fetus is subjected to hypoxia, has helped us recognize the early signs of IUGR thereby improving the prognosis of these complicated pregnancies. It has therefore become the gold standard in the management of the growth-restricted fetus.