Terminal myelocystoceles (TMCs) are a rare form of occult spinal dysraphism. They constitute approximately 5% of skin covered lumbosacral masses. The TMC is composed of a low-lying conus medullaris with cystic dilatation of caudal central canal, a surrounding meningocele and a lipoma that extends from the conus to a subcutaneous fat collection. A 6-month-old female child presented with a large lumbosacral mass (14 cm × 12 cm × 10 cm) and weakness at the ankle joints since birth. Magnetic resonance imaging and computed tomography scan revealed a low-lying terminal lipomyelocystocele with holocord syrinx and partial sacral agenesis. The child was operated on successfully. This is an interesting and rare case of giant terminal lipomyelocystocoele with syrinx and a partial sacral agenesis. Terminal lipomyelocystocele should be included in the differential diagnosis of congenital lesions presenting as a lumbosacral mass and operated early.