This article describes the psychometric characteristics of two major assessment instruments used in a World Health Organization (WHO) clinical trial: (a) Alcohol Timeline Followback (TLFB, which assesses daily drinking patterns), and (b) Inventory of Drinking Situations (IDS, which assesses antecedents to “heavy” drinking). Clients (N=308) were outpatient alcohol abusers from four countries (Australia, Canada, Mexico, and Sweden). Generally, the Alcohol TLFB and IDS were shown to be reliable and valid with outpatient alcohol abusers in four countries, and in three languages. These results suggest that the Alcohol TLFB and the IDS can be used in clinical and research settings with Swedish-, Spanish-, and English-speaking alcohol abusers.