Retinoids are synthetic vitamin A derivatives, particularly used in dermatology. Their prescription in women of childbearing age can cause, if pregnancy occurs, a serious malformative embryopathy, mainly involving external ear, brain and heart. A neonatal case caused by isotretinoin (RoAccutane) emphasizes the clinical and epidemiological data concerning this embryopathy. The aetiopathological hypothesis of an interaction between isotretinoin and Hox genes is advanced. Prophylactic measures are difficult since neonatal reported cases are uncommon, but antenatal exposition to this strong teratogenic agent results in multiple spontaneous abortions or pregnancy interruptions.