Internet addiction is a recently recognized disorder which has received increasing attention worldwide over the past two decades. This focus has led to the development of several screening tools measuring different aspects of Internet use, and more particularly Internet addiction. However, a synthesis of the information regarding the validity and usefulness of these different scales is lacking and would help inform researchers and clinicians in their choice of measures when assessing for Internet addiction. The main goal of this study was therefore to identify all the existing measures of Internet addiction and to review the psychometric properties of the most frequently used ones. Five electronic databases were searched using the key words: internet use disorder, Internet addiction, problematic internet use, pathologic internet use, cyber dependence, and scale, test, questionnaire, tool, assessment and inventory. Forty-five tools assessing Internet addiction were identified, of which only seventeen had been evaluated more than once in terms of their psychometric properties. Most of the existing scales for Internet addiction require further validation work but some of them already demonstrate promising psychometric properties. Given the interest in this phenomenon, it seems important for the field to promote the use of validated and well-established measures. 2014 Elsevier Ltd. All rights reserved.