Aim of this review is to highlight how and when Traumatic Brain Injury (TBI) as well as Subarachnoid Haemorrhage (SAH) and primary Brain Tumours (pBT) of the Central Nervous System (CNS) can induce hypopituitarism, an under-diagnosed clinical problem. Moreover, this review aims to clarify, on the basis of the recent evidences, how these patients have to be tested for pituitary-function. Both retrospective and prospective studies recommended that patients with more severe form of Brain Injuries (BI) and in particular, those with fractures of the base of the skull or early diabetes insipidus, have to be closely monitored for signs and symptoms of endocrine dysfunction. Further studies will be crucial to raise awareness and remind physicians on the prevalence of hypopituitarism in patients with BI and to elucidate any incremental benefits these patients may receive from hormone replacement.