Concern about Internet addiction, fuelled by the rapid increase in its usage across the globe, has spread to many parts of the world, including the Arab world. Concurrently, there has been a relentless quest for a valid tool for measuring Internet addiction. Thus far, two popular tools have been translated to Arabic: the Compulsive Internet Use Scale and the Internet addiction test (IAT). While the Arabic version of the former was proven valid by one study, the validity of the latter's Arabic version remains in question. Therefore, this study investigated the psychometric properties of the Arabic version of the IAT. An online Arabic version of the IAT was completed by 817 intermediate- and secondary-school students across Lebanon. The results showed that a one-factor model of the IAT has good psychometric properties and fits the data extremely well. This study presents evidence that the Arabic version of the IAT is valid for measuring Internet addiction among adolescents in Lebanon.