Although computers and the internet, indispensable tools in people's lives today, facilitate life on the one hand, they have brought new risks with them on the other. Internet dependency, or problematic Internet use, has emerged as a new concept of addiction. Parallel to this increasing in society in general, it is also on the rise among university students and is widely believed to have a negative impact on their lives. The aim of this study was to investigate whether academic self-efficacy and academic procrastination can act as predictors of problematic internet use among university students. The study group consisted of 398 students attending education, medicine, architecture and economics programs at the Karadeniz Technical University in Turkey. The Problematic Internet Use Scale, Academic Self-efficacy Scale, Academic Procrastination Scale and a Personal Data Form were used as scaling instruments. Pearson's correlation coefficient, multiple regression analysis, independent samples t-test and one-way ANOVA were used to analyze the data collected. The results show a significant negative correlation between academic self-efficacy and problematic internet use, while the relation between problematic internet use and academic procrastination was not statistically significant. Furthermore, academic self-efficacy was determined to be a significant predictor of problematic internet use. The results also show a significant difference in problematic internet use in terms of students' programs, though levels of problematic internet use did not differ in terms of sex or ownership of a computer. These findings are discussed in the light of the relevant literature and some new directions for further studies are suggested. (C) 2011 Elsevier Ltd. All rights reserved.