Objective: A specific and sensitive marker of alcohol abuse is serum γ-glutamyl transferase (GGT). A wide range of changes is met even between heavy drinkers. Through this work we wanted to see the variation of GGT according to age and alcohol consumption in patients with severe Alcohol Use disorders (AUD). We wanted also to evaluate the lower amount of alcohol, causing GGT elevation.Method: This is a retrospective study performed in American Hospital, Tirana, Albania during the period 2013-2015. Serum GGT values were measured in 157 patients diagnosed with severe AUD according to Diagnostic and Statistical Manual of Mental Disorders 5 edition (DSM-5) They were all males with mean age 42±4.9 years old, who presented voluntary in the hospital for alcohol detoxification. They were divided in subgroups according to age and alcohol amount consumption. Values are expressed as mean ±SD. Comparisons were made by logistic correlation. A P-value <0.05 was considered statistically significant. Results:We found a statistically significant correlation between GGT and ethanol intake (P<0.0001), (r=0.7) and a positive correlation between GGT and age. Normal mean values of GGT are found in the group of patients who consumed less than 10 drinks/day. 5-10 drinks/day was the limit to induce GGT elevation in our sample. Conclusion:Our findings show that GGT activities respond to ethanol intake and are age-dependent in patients with severe AUD. Early detection is associated to less complication and can lead to a better outcome.