OBJECTIVE: Patients who received pituitary-derived growth hormone (GH) are at excess risk of mortality from Creutzfeldt-Jakob disease. We investigated whether they were at increased risk of death from other conditions, particularly preventable conditions. STUDY DESIGN: A cohort (N=6107) from known US pituitary-derived GH recipients (treated 1963-1985) was studied. Deaths were identified by reports from physicians and parents and the National Death Index. Rates were compared with the expected rates for the US population standardized for race, age, and sex. RESULTS: There were 433 deaths versus 114 expected (relative risk [RR], 3.8; 95% confidence interval [CI], 3.4-4.2; P<.0001) from 1963 through 1996. Risk was increased in subjects with GH deficiency caused by any tumor (RR, 10.4; 95% CI, 9.1-12.0; P<.0001). Surprisingly, subjects with hypoglycemia treated within the first 6 months of life were at extremely high risk (RR, 18.3; 95% CI, 9.2-32.8; P<.0001), as were all subjects with adrenal insufficiency (RR, 7.1; 95% CI, 6.2-8.2; P<.0001). A quarter of all deaths were sudden and unexpected. Of the 26 cases of Creutzfeldt-Jakob disease, four cases have died since 2000. CONCLUSIONS: The death rate in pituitary-derived GH recipients was almost four times the expected rate. Replacing pituitary-derived GH with recombinant GH has eliminated only the risk of Creutzfeldt-Jakob disease. Hypoglycemia and adrenal insufficiency accounted for far more mortality than Creutzfeldt-Jakob disease. The large number of potentially preventable deaths in patients with adrenal insufficiency and hypoglycemia underscores the importance of early intervention when infection occurs in patients with adrenal insufficiency, and aggressive treatment of panhypopituitarism.