Traditional media (e.g. Radio, TV, Cinema, ...) have been playing an important part in the development of the glamorization of Alcohol and Tobacco products (A&T) (Austin and Pinkleton, 2016). The desirability associated to the use of A&T has been impacting the viewers, and particularly the most vulnerable ones as the children, more at risk of being influenced by the values surrounding the use of these product, and consequently, more likely to use these products in return (Nunez-Smith et al. 2010). This influence is now transposed on the new media, knowingly, the Social Networking Sites (SNS) (Gallopel-Morvan and Moodie, 2017). In order to minimize the influence of A&T products presented/placed on media popular within our vulnerable population that are the adolescents; it is important to develop the skills of these adolescents to resist this type of influence by developing their competences in SNS literacy. Different programmes could be created to develop the competences of adolescents to face the influential strategies integrated within the media posted online, however, the relevance of such programmes could be questioned (Austin and Pinkleton, 2016). This research programme intends to develop and validate a scale that could be used to assess the SNS literacy competencies of French adolescents. To our knowledge, no scale has been created and validated to evaluate such competences, even less for the French adolescents.