To investigate the clinical features, diagnosis and treatment in patients with subclinical pituitary adenoma apoplexy (SPAA). A retrospective analysis of all operated patients with SPAA was performed. There were 50 male and 80 female patients, ranging from 16 to 65 years (average 39 years). Endocrinological hormones were measured in all patients pre- and post-operatively, and pituitary imaging was obtained by CT scan, MRI or both. Transsphenoidal surgery was achieved in 89 patients, and transcranial surgery was achieved in 41 patients. There was no operative mortality. PRL adenomas were the most common tumor type (56.2%). SPAA usually occurred in patients with big or giant adenomas (97%). Hypertension and diabetes mellitus were the possible predisposing factors. Postoperative follow-up ranged from 0.5 to 6 years (mean 3.2 years). Tumor recurrence happened in 8 patients. Only 12 patients required radiotherapy with tumor residual (4 cases) and recurrence (8 cases) after surgery. Long-term thyroid or steroid hormone replacement was necessary in 25% and 20% of patients, respectively, and long-term desmopressin therapy was necessary in 1% of patients. The incidence of SPAA was higher than acute pituitary apoplexy. PRL adenomas are the most common tumor type. MRI is the best investigative modality of choice. Transsphenoidal surgery is a safe and effective method. The rate of long-term endocrinological hormones replacement therapy of SPAA is lower than acute pituitary apoplexy, and the prognosis of SPAA is better than acute pituitary apoplexy. Radiotherapy is indicated if the tumor residual or recurrence are confirmed by CT or MRI after surgery.