Torcular dural sinus malformations (tDSMs) can occur in the brain during prenatal development. These rare vascular malformations occur in less than 1% of the population but can lead to a poor prognosis secondary to congestive heart failure and hydrocephalus. Many tDSM cases require surgical embolization or coiling to return normal cerebral blood flow and prevent mortality and morbidity. We describe the first case of spontaneous self-embolization of a large torcular dural sinus malformation, possibly due to hypercoagulability from a comorbid prothrombin gene variant. Despite a grim prognosis at birth, the child is alive and thriving at age 3, with only mild speech delay.