TWEAK is an acronym for Tolerance (T1 number of drinks to feel high; T2, number of drinks one can hold), Worry about drinking, Eye-opener (morning drinking), Amnesia (blackouts), and Cut down on drinking (K/C). In this study, two versions (T1 and T2) of the TWEAK were part of a questionnaire used to detect alcoholism or heavy alcohol intake in three populations, namely, alcoholics in treatment, patients in two outpatient clinics, and the general population. Similar to the CAGE and the 10-item brief MAST, the TWEAK identified most known alcoholics, but the TWEAK had a higher sensitivity and specificity than the CAGE and B-MAST in detecting alcoholism/heavy drinking in the clinical and general populations. Different cut-off values for tolerance (T1 and T2) are recommended for screening different populations.