We report a case of isolated voluminous fetal ascites discovered during a routine fetal ultrasound at 22 weeks' gestation. Analysis of the fluid showed it to be chyliform and ruled out other causes of fetal ascites. Regular bimonthly ultrasound scans monitored its progressive diminution and then its disappearance. Examination showed the child to be normal at birth. Though the literature indicates that prognosis is usually favorable for infants with isolated fetal chylous ascites, spontaneous regression during pregnancy is an uncommon finding.