Objective: Carbohydrate-deficient transferrin (CDT) is a glycoprotein that contains sialic acid and is formed by reduction of carbohydrates in transferrin structure. In this study we planned to measure levels of CDT in patients with alcohol use disorders, cirrhosis, systemic lupus erythematosis (SLE). In this way, by looking at the first period, we aimed to show the utility of CDT in these diseases as a marker for early diagnosis. Methods: Twenty-nine patients with alcohol use disorders, 13 patients with cirrhosis, 17 patients with SLE and 31 healthy volunteers were included in the study. Serum CDT levels were measured by high performance liquid chromatography (HPLC) in all patients and healthy volunteers, and the means of the four groups were compared. Results: CDT levels in patients with alcohol use disorders, cirrhosis and SLE were determined as significantly high compared to the control group (p 1<0.001, p 2=0.027, p 3=0.001). Conclusion: The CDT level are useful as a diagnostic marker in patients with suspected alcohol use disorders, cirrhosis and SLE. ©Copyright 2011 by Gazi University Medical Faculty.