Fetal intrauterine growth restriction presents a complex management problem for the clinician. The failure of a fetus to achieve its growth potential imparts a significantly increased risk of perinatal morbidity and mortality. Consequently, the obstetrician must recognize and accurately diagnose inadequate fetal growth and attempt to determine its cause. Growth aberrations, which are the result of intrinsic fetal factors such as aneuploidy and multifactorial congenital malformations, and fetal infection, carry a guarded prognosis. However, when intrauterine growth restriction is caused by placental abnormalities or maternal disease, the growth aberration is usually the consequence of inadequate substrates for fetal metabolism and, to a greater or lesser degree, decreased oxygen availability. Careful monitoring of fetal growth and well-being, combined with appropriate timing and mode of delivery, can best ensure a favorable outcome. Ultrasound evaluation of fetal growth, behavior, and measurement of impedance to blood flow in fetal arterial and venous vessels form the cornerstone of evaluation of fetal condition and decision making.