No comprehensive benefit-to-cost analysis has been performed to date on a policy of routine ultrasound screening for fetal anomalies in the United States. We performed a preliminary benefit-to-cost analysis drawing upon our previous research on the cost or birth defects in the United States and upon the literature regarding (1) the sensitivity of ultrasound in detecting congenital anomalies, (2) the rate at which pregnancies are terminated upon detection of fetal anomalies, (3) the number of ultrasounds performed per pregnancy under a routine screening policy, and (4) the average cost of an ultrasound. We assumed a 100% subsequent replacement rate of terminated pregnancies with a normal child, an assumption most favorable to routine screening. The benefit-to-cost ratio ranged from .33 to 3, suggesting that a routine screening policy for fetal anomalies is of uncertain net societal benefit. Routine screening may be justified, however, based on standards that elude the methods for establishing societal benefits adopted in this analysis.