Vein of Galen malformations are rare congenital intracranial vascular malformations. Based on reports in the literature, spontaneous thrombosis or regression of these lesions is rare. Patients have variable outcomes from an asymptomatic course to death. The reasons behind spontaneous thrombosis are not entirely understood. Here the authors present a case of an infant diagnosed with a vein of Galen malformation in utero that subsequently went on to thrombose or regress. A review of the published cases on this phenomenon and the potential causality are discussed.