Meningeal hamartoma associated with spinal dysraphism in an elderly patient is an extremely rare clinical presentation. A 62-year-old woman who progressively developed gait disturbance and urinary retention was admitted to our hospital. Magnetic resonance imaging (MRI) revealed a large cystic mass associated with a dermal sinus at the L4-L5 level. MRI was useful in the diagnosis and determination of this lesion. However, preoperative differential diagnosis of the tumor was not possible based on neuroimaging evidence. The diagnosis of meningeal hamartoma was based on the histological and immunohistological findings of the specimen obtained from the tumor. Meningeal hamartoma associated with spinal dysraphism should be kept in mind, even in adult cases. In this article, we also discuss the radiological and pathological appearance of this rare clinical entity.