Complications of subarachnoid hemorrhage are the major life threatening and functional components of the follow up of a ruptured aneurysm. Knowing how to identify these is a key challenge. They vary in type throughout the postoperative follow up period. The aim of this article is firstly to list the main complications of the acute phase (rebleeding, acute hydrocephalus, acute ischemic injury and non-neurological complications), the subacute phase (vasospasm) and the chronic phase of subarachnoid hemorrhages: (chronic hydrocephalus and cognitive disorders) and to describe their major clinical and radiological features. Secondly, we describe the long-term follow up strategy for patients who have suffered a subarachnoid hemorrhage and have been treated endovascularly or by surgery. This follow up involves a combination of clinical consultations, cerebral MRI and at least one review angiogram.