A survey of 488 college students was conducted in Turkey to investigate the relationship between social network usage, shame and Internet addiction. It was hypothesized that a relationship between shame and social network usage was mediated by Internet addiction. First of all, according to simple regression analysis, it was found that shame significantly and positively predicted social network usage. A simple mediation model, which was applied with regression-based mediation analysis, showed that shame did not predict social network usage when Internet addiction was inserted in the model. Therefore, Internet addiction is a mediating variable between shame and social network usage. According to the results of mediation analysis, Internet addiction of college students is an important predictor in terms of social networking site (SNS) usage.