Pituitary adenoma is a common primary brain neoplasm. Pituitary apoplexy (PA) is a rare complication of pituitary adenoma and occurs as the result of sudden tumor growth and following different comorbidities. The authors describe the first case of PA following posterior lumbar fusion surgery performed while the patient was prone. In patients with a preexisting pituitary adenoma, thorough clinical and laboratory investigations should be conducted using an interdisciplinary approach before any planned surgery. In unknown cases of pituitary adenoma, PA should be kept in mind for the differential diagnosis in a case with headache, nausea, vomiting, ophthalmoplegia, visual loss, and electrolyte imbalance concurrent with an ongoing disease state.