A 40-year-old woman with Cushing's disease presented with hypertensive cerebral hemorrhage. Neuroimaging detected an unruptured large intracavernous aneurysm, which projected beyond the midline, and thin crescent-shaped adenoma along the aneurysm wall. The aneurysm was treated with endovascular tight packing with coils. Transsphenoidal adenomectomy was then safely performed. The signs of Cushing's disease were resolved, and she was discharged without deficits. The first line therapy for Cushing's disease is transsphenoidal adenomectomy. However, the therapeutic strategy and optimal timing of treatment are unclear for Cushing's disease with large intracavernous aneurysm. The present case shows that transsphenoidal surgery was safely possible with minimal invasiveness after embolization of the intracavernous aneurysm.