We report on a fetus of 27 weeks of gestation whose clinical, radiological, and histopathological findings are compatible with the prenatal form of Caffey disease (cortical hyperostosis). Prenatal ultrasound examination showed polyhydramnios and markedly short and angulated long bones, which had led to the incorrect diagnosis of lethal osteogenesis imperfecta. We found 43 published descriptions on the antenatal onset of cortical hyperostosis symptomatic in utero or at birth. Two groups of prenatal cortical hyperostosis (PCH) can be distinguished: (1) severe (25 reports and the fetus presented here), with onset before 35 weeks of gestation and generally associated with polyhydramnios, lung disease, prematurity, and high lethality; (2) mild (18 reports), with onset after 35 weeks of gestation and without complications. Autosomal recessive inheritance has been suggested for the prenatal form of cortical hyperostosis. However, the available evidence suggests that both dominant and recessive inheritance is possible. Moreover, dominant inheritance seems to be more common in the mild prenatal form of cortical hyperostosis. © 2003 Wiley‐Liss, Inc.