Abstract: Objective: To explore the effect of single-nostril transsphenoidal approach on pituitary adenoma. Methods: We retrospectively analyzed 46cases of pituitary tumors treated with single-nostril transsphenoidal approach and the ef -fects and complications of surgery. During the surgery, a nasal speculum was inserted through right nostril slowly towards the anterior wall of sphenoid sinus. A nasal mucosa incision of about 1.5cm was made in the right nasal cavity at the level of the middle nasal turbinate. With a fracture of the bony septum, a space was developed between the bilateral nasal muco-sa and bony septum to the sphenoid sinus. Then, the face of the sphenoid sinus was exposed. The remainder of the bony septum, the anterior sphenoid sinus wall, and the sphenoid mucosa were removed. The anterior sphenoidotomy should be less than 1.5cm wide. After confirming the tumor by dural puncture, a cross incision of dura was made and the tumor was removed. The saddle was usually collapsed and visible after total tumor removal. When the tumor was resected, sevaral gelatin sponges were stuffed into the surgical cavity to stop bleeding.Results: Thirty-four cases had total resection and12 cases had subtotal resection. No deaths or disability occurred. Hormone levels in almost all patients were improved. Seven-teen cases had a sign of diabetes insipidus. Electrolyte disturbance occurred in 5 cases. No postoperative cerebrospinal flu-id rhinorrhea was observed. Conclusion:Single-nostril transsphenoidal approach has many advantages in treating pituitary adenomas such as simplified approach, brief technology and high security.