Abstract INTRODUCTION Transsphenoidal encephalocele (TSE) is a rare type of basal encephalocele (BE) with a reported incidence of 1 in 700 000 live births. Clinical presentation is often insidious with a large herniation protrudes through the nasopharynx containing neural elements. Due to the rare occurrence of these lesions, management options can be quite challenging. METHODS Authors present a case report of a 16-yr-old male who has followed for a large transsphenoidal encephalocele. The patient had obstructive sleep apnea with a recent progression of his vision and endocrinopathy symptoms. Unique is the preoperative planning and the surgical details to treat this complex developmental pathology of skull base. RESULTS The timing of mangement of the transsphenoidal encephalocele depends on the progression. Endoscopic endonasal transsphenoidal approach was utilized to address this skull base defect. A large herniation containing neural elements was encountered and was sequentially reduced. Authors discuss their novel method of closing the bone defect with an autologous calvarial partial thickness parietal bone graft. Postoperative course was uneventful. Postoperative MR brain revealed significant reduction of TSE with closure of the bony defect. CONCLUSION TSE can be closely monitored; however, surgery is recommended in lieu of progression of symptoms. Sphenocranioplasty with a partial thickness calvarial bone graft through endoscopic endonasal transsphoidal approach is a viable option to treat this rare developmental pathology of skull base.