This research aims at examining the relationships between problematic internet usage (PIU) behavior and some demographic information and qualifications related to internet use of Turkish university students. The research was conducted with 2084 university students. Data was collected by means of Problematic Internet Usage Scale (Ceyhan, Ceyhan & Gurcan, 2007) and a questionnaire. The findings indicate that the males' PIU levels were significantly higher than females. Individuals' PIU levels did not reveal a significant difference in terms of the length of the regular internet usage time and grade groups. In terms of pairwise comparisons of CumGPA groups, only the less successful group (0-1.99) had significantly higher PIU level than the more successful group (3.00-4.00). The more the individuals' average weekly usage span of internet increased, the more the PIU levels raised. Individuals' PIU levels also differentiated significantly according to competence levels regarding internet usage and primary reasons to use internet.