Diagnosis of Creutzfeldt-Jakob disease (CJD) at lifetime according to the international diagnostic criteria may be greatly improved by the additional assay of 14-3-3 protein in cerebrospinal fluid (CSF). Occurrence of 14-3-3 protein in CSF may be observed in etiologically different conditions of brain damage, but confers high diagnostic specificity in cases of suspected CJD based on the diagnostic criteria. We investigated the occurrence of 14-3-3 protein in CSF of 20 patients with an accompanying diagnosis "suspected CJD", of whom 5 cases had to be classified as neither probable nor possible CJD according to the international diagnostic criteria, as well as in 18 control cases with diseases other than CJD. Assay of 14-3-3 comprised SDS-PAGE, western blot, immunostaining with specific antibody, and luminiscence detection. With regard to case histories at the end of our study, 8 definitive and probable CJD cases were 14-3-3 positive and 2 possible CJD cases 14-3-3 negative. Of the 10 cases with final diagnosis other than CJD, 8 cases (in part with manifest or suspected brain damage; one case with hemorrhagic CSF) were 14-3-3 positive. Of the 18 controls with diseases other than CJD, 6 patients, characterized by brain tissue lesions or meningitis, respectively, were found to be 14-3-3 positive. Our observations, the first in Austria and on a limited number of patients yet, are in accordance with previous reports in the literature and further support the use of the 14-3-3 protein assay in CSF as a diagnostic tool for CJD, provided that probands had been pre-evaluated positively by the international diagnostic criteria for CJD.