Frontonasal dysplasia is an etiologically heterogeneous development alteration including a set of anomalies affecting the eyes, forehead, and nose as a result of a malformation of the frontonasal elevation. It could occur either in isolation or as part of a syndrome such as frontonasal dysplasia associated with periventricular heterotopia. Our goal is to document the first clinical case of prenatal diagnosis for frontonasal dysplasia associated with periventricular heterotopia by fetal magnetic resonance imaging (MRI) at weeks 19.5 and 29 and postnatal MRI. In conclusion, the presence of frontonasal dysplasia in a prenatal ultrasonography should always be followed by a fetal MRI with routine screening for periventricular nodular heterotopias so as to establish a more adequate prognosis for the family.