Temporal lobe meningoencephalocele in the lateral sphenoid sinus is an uncommon, and potentially dangerous, pathological condition. Adult patients with meningoencephalocele in the sphenoid sinus often present with spontaneous cerebrospinal fluid rhinorrhea and should be considered for transsphenoidal or transcranial repair. Surgical repair of this fistula is recommended in order to reduce the risk of meningitis. Temporal lobe encephaloceles in the lateral sphenoid sinus have rarely been reported. Careful preoperative evaluation and localization of the sphenoid defect are critical for the selection of the optimal surgical approach for the repair of the skull base defect. Unfortunately, the definite location of the fistula is often difficult to establish. In this report, we present a 42-year-old female who had cerebrospinal fluid (CSF) rhinorrhea without meningitis for three years. We also discuss the relevant medical literature emphasizing the difficulty of making the diagnosis and the treatment approach.