Carbohydrate-Deficicnt transferrin (CDT) is a protein identified by Stibler et al. (1986). This proteins appearance may be a response to acetaldehyde which alters transferrins terminal glycosylation and transport. A total of 21 controls and 62 patients were assayed using conventional biologic markers, CDT, and the CAGE questionnaire. A gender-dependent control range is established and a significance model @ < .OOOI) is presented using CDT, gamma glutamyl transpeptidase (GT), and the CAGE questionnaire. The association of this marker with established screening tools demonstrates potential in both clinical screening and forensic medicine in identifying excessive alcohol consumption. [Arlicfe copies available fmnt The Haworlh Document Delivery Sewice: 1-800-342-9678. E-mail address: getinfo@aworth.com] Richard F. Hemdon and Cecelia Subauste are affiliated with Southern Illinois