We investigated %CDT (carbohydrate-deficient transferrin) in 92 ethanol-intoxicated alcohol-dependent patients after consecutive admission to hospital and followed the for 28 days under controlled conditions. At admission, 63% (58 patients) showed elevated CDT (> 2.5%) and 34 patients (37%) had normal CDT levels (< 2.5%). No correlation of the %CDT values to alcohol-related disabilities, severity of the withdrawal syndrome, alcohol-drinking pattern before admission, or several other factors was found. The sensitivity of GGT (gamma-glutamyl transferase) was 58% for the same group of patients. Levels of %CDT decreased during the 28 days following abstinence, whereby we could separate four statistically different groups of "CDT decrease'. In two of these groups, comprising most of the cases studied, normal %CDT levels were reached after 14 days of abstinence. Those patients with %CDT levels exceeding the upper normal level after 14 days of sobriety, showed a decrease during the following 14 days to levels of 2.55-2.61%.