The proper management of intracranial arterial aneurysms has been the object of considerable controversy. In an effort to evaluate various methods of treatment, we have compared the results of these methods in 115 patients treated under similar conditions by the same surgeons. Before the evolution of modern neurosurgical techniques, intracranial aneurysms were curiosities, usually discovered at autopsy. In 1923 Symonds'1presentation of the criteria for the diagnosis of a ruptured intracranial aneurysm gave impetus to further study of this subject. Richardson and Hyland,2Walsh and King,3Dandy,4and numerous others have contributed much to the increasing frequency of diagnosis and successful treatment of aneurysms. Recently a more complete study by Hamby5has brought the entire subject into focus with a survey of the previous publications and an analysis of his own material. The mortality rate of ruptured intracranial aneurysms is known to be high, ranging