Surgery of pituitary adenomas invading cavernous sinus has always been thought as a challenge due to the complex anatomical structures and high risk of complications. The purpose of this study was to evaluate endoscopic transsphenoidal approach to pituitary adenomas invading cavernous sinus. The clinical data of 22 patients who admitted to Xuanwu Hospital with pituitary adenomas invading cavernous sinus were analyzed retrospectively. All patients underwent endoscopic transsphenoidal surgery. To expose the surgical field sufficiently, the opening of sellar floor was exceeded the bone overlying the invaded cavernous sinus, and synthetic dura was used to repair and strengthen the sella floor for preventing the leak of cerebrospinal fluid. Among 22 patients, total resection was achieved in 14, subtotal resection in 5, and partial resection in 3; no patient underwent insufficient resection. Visual symptoms improved in 7 of 9 patients. In one patient diplopia disappeared. Headache was relieved to various extents in all patients. No serious complications were found. Patient's hospital stay ranged from 7 to 20 days. These data suggest that the endoscopic transsphenoid approach is a safe, minimally invasive, and efficient surgical technique, which might be an important therapeutic strategy for the pituitary adenoms invading cavernous sinus.