Invasive pituitary adenomas (IPA) involving the skull base extend from the sella region, and invade surrounding structures. In the present study, we reviewed the therapeutic efficacy in a group of patients with IPA treated with endoscopic endonasal transsphenoidal surgery. Data from 78 IPA patients at our hospital were retrospectively reviewed. The diagnostic modalities, surgical techniques, and outcomes were reviewed. Diagnosis was confirmed by endocrinological profile and CT or MRI in all patients. Surgery was performed via an endoscopic endonasal transsphenoidal approach. Thirty-five patients (44.9%) had hormonally active tumors, and 43 (55.1%) had nonfunctioning tumors. Complete removal of the tumor was achieved in 62 patients (79.5%) and subtotal removal in 12 (15.4%); partial removal was achieved in the remaining four patients (5.1%) who had fibrous or dumbbell-shaped adenomas. The mean follow-up was 43.2 months in 65 patients and the clinical symptoms in all patients improved to varying degrees. In 52 patients, the tumors completely disappeared on follow-up imaging. Visual symptoms improved in 96.4% of the patients who had presented with visual impairment. These surgical results show that endoscopic endonasal transsphenoidal surgery for resection of IPA has advantages. We suggest that the endoscopic endonasal transsphenoidal surgery method is a safe, minimally invasive and efficient surgical technique for removal of IPA, providing good visualization of the operative field, generally complete tumor removal, short procedure duration, and minimal postoperative complications.