The authors present an endoscopic endonasal transpterygoid approach for reduction of a lateral recess encephalocele with post-operative cerebrospinal fluid leak. A 43-year old male presented with right-sided clear rhinorrhea for 2 years. He had no other sinus complaints. On examination, he had a BMI of 28 and right-sided clear rhinorrhea while leaning his head forward. This fluid was collected and found to be positive for Beta-2 Transferrin. The patient had no history of meningitis, trauma, obstructive sleep apnea, idiopathic intracranial hypertension, or any recent weight changes. CT and MRI of the skull base were obtained. The steps of the transpterygoid technique and reconstruction are explained in detail through the video. Post-operatively, the patient had no bedrest precautions. Sixteen hours after surgery, the patient began to have clear rhinorrhea. The index of suspicion for a cerebrospinal fluid leak was high, and the decision was made to take the patient back to the operating room for re-exploration on post-operative day 2. From this case, we can learn from several technical errors through demonstrating the pitfalls and nuances of the technique. First, full reduction of the encephalocele helps to identify margins of the skull base defect. It is also essential to ensure appropriate preparation of the nasoseptal flap recipient site by skeletonizing the skull base, including removal of residual bony edges and removal of sphenoid sinus mucosa.