Some Internet users find it difficult to control the time spent on the Internet, which can lead to a negative impact on school, work and relationships with friends and family. The main goal of the present study was to assess the prevalence of compulsive social networking using the Compulsive Social Networking Scale (CSS) and to determine the profile of compulsive versus non-compulsive users of SNSs by means of a cross-sectional survey among 1002 Belgian adolescents. The results indicate that respondents had an average score of 0.85 on the CSS (range 0–4). When applying a cut off of 2 and more, this resulted in 7.1 % compulsive users. Results showed that both personality traits (6 %) and psychosocial well-being (7.3 %) explain significant amounts of variance above gender and age. In sum, the block of age and gender together with personality and psychosocial well-being explains 15.8 % of the variance.