The purpose of this research is to examine the relationship of Internet addiction, social self-efficacy, and academic locus of control. Participants were 311 university students who completed a questionnaire package that included the Online Cognition Scale, the Academic Locus of Control Scale, and the Perceived Social Self-efficacy Scale. The hypothesis model was tested through structural equation modeling. According to results internal academic locus of control was predicted positively by social self-efficacy. Also internet addiction was explained negatively by social self-efficacy and internal academic locus of control and positively by external academic locus of control. Results were discussed in the light of literature. (C) 2009 Elsevier Ltd. All rights reserved.