A case report is presented herein of a 33-year-old woman with a history of congenital adrenal hyperplasia in 2 prior births. At 30 weeks of gestation, a scan of the fetal perineum demonstrated ambiguous genitalia which was confirmed at birth. This case demonstrates that when the fetal perineum is well visualized, the diagnosis of normal and abnormal genital development can be made sonographically. This can assist in perinatal/neonatal management, planning and in some cases, can also serve as an additional tool to monitor the success of prenatal steroid therapy of fetal congenital adrenal hyperplasia.