OBJECTIVE Recovery from preexisting hypopituitarism after transsphenoidal surgery for pituitary adenoma is an important outcome to investigate. Furthermore, pituitary function has not been thoroughly evaluated after fully endoscopic surgery, and benchmark outcomes have not been clearly established. Here, the authors characterize pituitary gland outcomes with a focus on gland recovery following endoscopic transsphenoidal removal of clinically nonfunctioning adenomas. METHODS This multicenter prospective study was conducted at 6 US pituitary centers among adult patients with nonfunctioning pituitary macroadenomas who had undergone endoscopic endonasal pituitary surgery. Pituitary gland function was evaluated 6 months after surgery. RESULTS The 177 enrolled patients underwent fully endoscopic transsphenoidal surgery; 169 (95.5%) of them were available for follow-up. Ninety-five (56.2%) of the 169 patients had had a preoperative deficiency in at least one hormone axis, and 20/95 (21.1%) experienced recovery in at least one axis at the 6-month follow-up. Patients with adrenal insufficiency were more likely to recover (10/34 [29.4%]) than were those with hypothyroidism (8/72 [11.1%]) or male hypogonadism (5/50 [10.0%]). At the 6-month follow-up, 14/145 (9.7%) patients had developed at least one new deficiency. The study did not identify any predictors of gland recovery (p ≥ 0.20). Permanent diabetes insipidus was observed in 4/166 (2.4%) patients. Predictors of new gland dysfunction included a larger tumor size (p = 0.009) and Knosp grade 3 and 4 (p = 0.051). CONCLUSIONS Fully endoscopic pituitary surgery resulted in improvement of pituitary gland function in a substantial minority of patients. The deficiency from which patients were most likely to recover was adrenal insufficiency. Overall rates of postoperative permanent diabetes insipidus were low. This study provides multicenter benchmark neuroendocrine clinical outcome data for the endoscopic technique.