Introduction. The vascular structures in the central nervous system has a particular distribution in respect of other organs. This anatomic configuration and other conditions predispose this arteries and veins to bleed frequently in the subarachnoid space, resulting in a syndrome known as subarachnoid hemorrhage. Development. We make a study of the bibliography published in the topic, beside our professional criteria concerning those themes, with regard to the elements that we have been able to evaluate in our daily practice. We carried out a wide review about etiology, physiopathology, clinical presentation, diagnosis and management of the commonest problems associated with that entity. Specially those aspects related with the clinical support and treatment of the cerebral vasoespasm, hydrocephalus and other complications of the subarachnoid hemorrhage. Conclusion. In this paper we expose the most important aspects related with the clinical manifestations of certain vascular malformations like saccular aneurysm and arteriovenous malformations, the principles of it diagnosis and management.