Congenital adrenal agenesis is an extremely rare condition wherein the adrenal glands fail to develop. The absence of adrenal tissue results in the complete absence of hormones produced in the adrenal cortex (cortisol, aldosterone) and medulla (catecholamines), and is not compatible with postnatal life without artificial hormone replacement therapy. To date, 9 cases of adrenal agenesis have been reported, many of which are associated with additional congenital anomalies. Most cases were not detected on antenatal imaging and were detected incidentally at postmortem examination. We present a case of adrenal agenesis, detected incidentally at postmortem examination after termination of pregnancy for suspected fetal hydrops, and review the heterogeneous phenotype of this condition with associated abnormalities and molecular genetics. This case reinforces the role of the perinatal autopsy to investigate cause of perinatal mortality, allowing correlation of pathology with antenatal imaging findings and clinical details.