Leptomeningeal cyst, or growing skull fracture, is a rare complication of pediatric head trauma. This entity is typically diagnosed several weeks or months following head trauma when an enlarging scalp mass is recognized. Progressive neurologic deficits (seizures, paresis) can accompany this process, which typically do not improve following conventional surgical treatment. Given that radiographic findings are highly predictive of which children are likely to develop a leptomeningeal cyst, we have adopted a policy of early management in an effort to avoid difficult surgical dissections and progressive neurologic sequelae seen with delayed intervention. The cases of two infants with skull fractures are used to illustrate our approach toward early management of post-traumatic leptomeningeal cysts.