Enlarged fetal kidneys are characteristic of more than one possible diagnosis. Though infantile polycystic kidney disease is probably the most well known entity and is associated with oligohydramnios, Beckwith-Wiedemann syndrome should be considered in the differential diagnosis especially if a normal or increased amount of amniotic fluid is present. The presence of an omphalocele with a normal karyotype should also arouse suspicion. This constellation of findings carries potential morbidity including macrosomia, fetal hypoglycemia, mental retardation, microcephaly, increased risk of subsequent neoplasia, and even neonatal death. Beckwith-Wiedemann syndrome may not be obvious in the newborn period.