Patients with severe craniocerebral trauma (sCCT) display metabolic and endocrine changes. The question is raised whether hormonal patterns give cues to the prognosis of outcome or not. In 21 patients the function of the adrenocortical, gonadal, thyroid and human growth hormone (hGH)-insulin system was assessed. LH, FSH, TSH, prolactin and hGH were stimulated. 3 groups of patients were formed. Group I: patients in acute phase with a Glasgow Coma Score (GCS) more than 6 (group Ia) and less than 6 (group Ib). Group II: patients in transition to traumatic apallic syndrome (TAS). Group III: patients with full-blown or resolving TAS. The values of group Ia comprised low T3, T4 and testosterone, elevated insulin, normal hGH. Group Ib had hypothyroid T3 and T4 and an attenuated response of LH, TSH, prolactin and hGH to stimulation. Group III: there was seen an endocrine normalisation with elevated T4 and TBG and an altered response of hGH and prolactin to stimulation. Endocrine abnormalities were not helpful in predicting which course, either to better or to worse, a given patient would follow.