The purpose of this research is to examine the relationship between Internet addiction and psychological well-being. Participants were 479 university students who completed a questionnaire package that included the Online Cognition Scale and the Scales of Psychological Well-Being. The relationships between Internet addiction and psychological well-being were examined using correlation and multiple regression analysis. According to results, psychological well-being was predicted negatively by diminished impulse control, loneliness/depression, social comfort, and distraction. Students with higher levels of Internet addiction are more likely to be low in psychological well-being. The results indicated that psychological well-being was affected by Internet addiction negatively; and provided a better understanding on the relationship between psychological well-being and Internet addiction.