INTRODUCTION To examine the prevalence and outcome of absent ductus venosus (DV) diagnosed at 11-13 weeks' gestation. METHOD Prospective screening study for aneuploidies in 65,840 singleton pregnancies, including measurement of nuchal translucency (NT) thickness and examination of the DV. Prenatal findings and outcome of fetuses with absent DV were examined. RESULTS Absent DV was diagnosed in 26 cases giving a prevalence of 1 in 2,532. In 15 (57.7%) cases the NT was above the 95th centile for crown-rump length. In 11 (42.3%) cases, there was an aneuploidy, mainly Turner syndrome. The incidence of aneuploidies was 66.7% (10 of 15) for those with NT above the 95th centile and 9.1% (1 of 11) in those with normal NT (p = 0.015). In addition to the aneuploidies, there were 3 cases with other abnormalities, including one case each of Ebstein anomaly, Noonan syndrome and Pierre Robin sequence. In 9 of the 11 (81.8%) fetuses with NT below the 95th centile, absent DV was an isolated finding and the pregnancies resulted in healthy live births. CONCLUSION The prognosis of fetuses with absent DV depends on the measurement of NT thickness, being poor if the NT is increased and good if the NT is normal.