The anterior communicating artery represents one of the commonest sites of intracranial aneurysms.Clinical diagnosis depends in most cases on the development of S.A.H. and its complications after aneurysmal rupture.Radiologic studies play an important rule in the diagnosis of intracranial aneurysms and S.A.H that based on two steps:1) Diagnosis of SAH that depends mainly on brain C.T.2) Diagnosis of the aneurysm: four vessel angiography is the corner stone for its diagnosis. Treatment is based on many lines including:1) Medical treatment for: SAH, its complications especially vasospasm and treatment of the medical problems especially hypertension.2) Surgical treatment: based on clipping of the aneurysms with aneurysmal clips.3) Endo vascular treatment by balloons and Micro coils to occlude the aneurysm sac, or micro angioplasty to treat complications as vasospasm.