Sonographic technology has given the prenatal diagnostician the ability to accurately visualize fetal malformations. This article demonstrates the currently available capability of applying sonographically derived information concerning fetal dysmorphology to our knowledge of genetic disorders and syndromes. As a result, there can be a significant improvement in the management and counseling of these patients. After an initial discussion of normal embryology, principles of abdominal ultrasonography are discussed and applied to the following anomalies: omphalocele, gastroschisis, diaphragmatic hernia, duodenal atresia, other intestinal atresias and stenoses, renal anomalies, and obstructive uropathies.