Measures of adaptive behaviors provide an important tool in the repertoire of clinical and school/educational psychologists. Measures that assess adaptive behaviors typically have been built in Western cultures and developed in light of behaviors common to them. Nevertheless, these measures are used elsewhere despite a paucity of data that examine their cross-national transportability. The issue of test transportability of such measures is important because they are used in cultures that differ from those in which they initially were developed as well as with immigrants. This present article describes the Romanian and Taiwan adaptation process of the U.S.–developed Adaptive Behavior Assessment System, Second Edition (ABAS-II) Parent Form for ages 5 to 21. Steps taken to help ensure a valid translation and cultural adaptation process are described. Data from more than 3,000 parents who completed the ABAS-II are examined across these three test versions, focusing on score differences, internal consistency, intercorrelations, and factor structure equivalence. Data from the three versions display considerable similarity. Score differences are infrequent between the three versions yet display some differences mainly at lower ages. Scale reliabilities are high and comparable for all the three versions. Correlation patterns are sufficiently similar between the three versions. Confirmatory factor analyses show a similar fit for all three versions.