Fetal omphalocele and gastroschisis are congenital defects of the abdominal wall that require prompt surgical management at the time of delivery. To evaluate the role of prenatal sonography in identifying factors that influence prognosis, 24 cases of abdominal-wall defect (16 omphalocele, eight gastroschisis) were reviewed. Sonograms were evaluated for location of umbilical cord insertion, contents of the ventral defect, presence or absence of a covering membrane, fetal ascites, bowel-wall thickening, and coexisting anomalies. Sonographic differentiation between omphalocele and gastroschisis was possible in 18 (75%) of 24 cases. Eighteen patients had congenital defects in addition to the abdominal-wall defect. Associated abnormalities were present in 14 (88%) of 16 fetuses with omphalocele and four (50%) of eight with gastroschisis. Overall survival rate was 50%, excluding six terminated pregnancies. Survival rate was 33% for neonates with omphalocele and 83% for those with gastroschisis. The better prognosis for neonates with gastroschisis appears to reflect the lower frequency of associated congenital anomalies.