Fetal magnetic resonance imaging is increasingly being used as an adjunct to ultrasound. It allows for better visualization of in utero brain development and intracranial abnormalities (especially cerebral malformations). Hypothalamic hamartoma is a nonneoplastic malformation resembling normal hypothalamic tissue both histologically and on magnetic resonance imaging. Although it is rare, this entity is important to recognize for appropriate management and genetic counseling. We describe a unique patient in whom magnetic resonance imaging of the fetal brain allowed a prenatal diagnosis of Pallister-Hall syndrome.