This book provides a detailed introduction to the characteristics of cerebral aneurysms and the current treatment methods. Cerebral aneurysms are not rare, and they have a high disability and mortality rate. Most patients are unaware that they have a cerebral aneurysm, with the most common being cerebral hemorrhage. The diagnosis and treatment of cerebral aneurysms have been ongoing for more than 100 years. We have achieved excellent results, but there are still many things that we do not know. An increasing number of unruptured cerebral aneurysms are accidentally discovered during neuroimaging examinations. The greatest risk of cerebral aneurysm is the risk of rupture. Due to the extremely high mortality rate, once these aneurysms are detected, systematic treatment is necessary. The earlier a patient is referred to a neurosurgeon or interventional neuroradiologist, the better the outcome will be compared to the patient experiencing rupture. The decision to treat is multifactorial.