Computer-assisted tomography (CT) with 2 mm axial sections and reconstructions was carried out in 31 children affected by GH deficiency (GHD): 18 with idiopathic complete isolated GHD, 3 with idiopathic partial isolated GHD, 2 with idiopathic panhypopituitarism, 4 with isolated acquired GHD and 4 with acquired panhypopituitarism. Density in the intrasellar area on CT corresponded to that of cerebrospinal fluid in 13/20 cases with idiopathic hypopituitarism and in 2/8 cases with acquired hypopituitarism. The overall incidence of primary empty sella syndrome (PESS) in the GH deficient patients studied was thus over 48%, while in children without endocrine dysfunction, it was only 5/213 (2.4%). It is concluded that PESS is more frequent in childhood than assumed until now and that it is frequently associated with GHD.