After aneurysmal subarachnoid hemorrhage (SAH), patients frequently present with persistent bodily, psychosocial, and cognitive impairments that resemble those of patients with untreated partial or complete pituitary insufficiency. Because of these similarities, the authors hypothesized that aneurysmal SAH may cause pituitary dysfunction. Pituitary function testing was performed in 40 aneurysmal SAH patients between 12 and 72 months after the SAH. A combined TRH-LHRH-arginine test and the insulin tolerance test were performed on two separate days. Only 18 of 40 (45%) of the tested patients had normal pituitary function. Five of 40 exhibited isolated severe GH deficiency (GHD), and an additional three of 40 had severe GHD plus corticotroph deficiency. Isolated corticotroph deficiency was seen in 13 of 40 patients, and one patient showed isolated thyrotroph deficiency. All but one patient with corticotroph insufficiency were female. Patients with severe GHD had gained significantly more weight since their SAH than patients without GHD and exhibited a significantly higher body mass index. None of the clinical parameters indicative of a poor neurological outcome in aneurysmal SAH were related to pituitary insufficiency. In summary, neuroendocrine dysfunction was identified in a substantial portion of patients with previous aneurysmal SAH and should be borne in mind as a potential long-term sequel of the illness.