Introduction: the spontaneous subarachnoid hemorrhage is the extravasation of blood into the subarachnoid spaces, its most frequent cause is the rupture of an intracranial aneurysm. Objective: to characterize clinically and epidemiologically and anatomopathologically the spontaneous subarachnoid hemorrhage in the "Arnaldo Milián Castro" Hospital during 2018. Methods: a descriptive observational study was carried out, of retrospective longitudinal cut, in the period from January to December 2018. The sample to be studied consisted of 32 patients. Results: the most affected sex was female (19, 59.4%), the predominant cause was aneurysmal (17, 53.1%), followed by arterial hypertension (18.8%), vasospasm (34.4%) and endocranial hypertension (21.9%). Conclusions: the most affected sex was female and, in relation to age, the 60 to 69 years age group was more predominant. The predominance of aneurysmal causes was determined, followed by those secondary to arterial hypertension, and the most frequently affected arteries were the middle cerebral and posterior communicating arteries. The most frequent complications were rebleeding and endocranial hypertension. The majority of patients had a fatal outcome and the aneurysmal cause predominated according to the anatomopathological report.