Objective To investigate the therapeutic effect and operation skills of subtemporal keyhole approach for the treatment of invasive pituitary adenoma occupying the middle and posterior cranial fossae.Methods Four patients with invasive pituitary adenoma were treated with endoscope-assisted subtemporal keyhole approach for excision of the tumor, and endoscopic observation was performed during surgery. The surgical outcomes were evaluated based on MRI and endocrine levels.Results All cases underwent subtotal resection of pituitary adenoma. After operation, 2 cases had decreased hormone levels, and all had markedly relieved headache and dizziness. In the 2 cases of pituitary adenoma invading the cavernous sinus, 1 had cranial nerve dysfunction (diplopia) after operation, and the other had hypopituitarism. Six months of follow-up revealed no tumor recurrence.Conclusions Endoscope-assisted subtemporal keyhole approach is feasible for the treatment of pituitary adenoma in the middle and posterior cranial fossae. The prerequisites for such operation in the treatment are familiarity with the anatomy, microsurgical skills, and rich operation experience.