The coexistence of pituitary adenoma (PA) and anterior communicating artery aneurysm is extremely rare, making the diagnosis difficult and the treatment challenging. Herein, we present a PA patient with intracranial hemorrhage due to rupture of an anterior communicating artery aneurysm. For the best diagnosis of intracranial aneurysm among PA patients, cranial magnetic resonance together with three-dimensional time-of-flight magnetic resonance angiography are strongly recommended. Previous treatment of the intracranial aneurysm is advisable and essential to avoid possible catastrophic bleeding during the transsphenoidal or microsurgical removal of PA.