A 30-year-old female presented with a long history of dysmenorrhea and severe constipation. Radiological evaluation and magnetic resonance imaging revealed findings characteristic of an anterior sacral meningocele. Surgical treatment through the posterior transsacral approach failed, because the neck and orifice of the meningocele were too large to perform a simple neck ligation. A second operation successfully resected the connecting dural stalk of the meningocele and reconstructed the thecal sac. Microsurgical reconstruction of the thecal sac through the transsacral approach is a favorable option even for a large meningocele with a wide neck and ostium.