The purpose of this study is to investigate the internet use of Turkish adolescents, with a (particular) focus on the risk of Internet addiction. A web-based questionnaire was completed by a total of 4,311 adolescents attending public high schools in grades 9-12, in a small-sized city in western Turkey. Ages ranged from 15 to 19 years, 54 percent were female and 46 percent male. The questionnaire included items on sociodemographic information, Internet usage, and a Turkish version of the Young's Internet Addiction Test. The data were analyzed in SPPS 15.0 program using the t test, the Mann-Whitney U test, correlation and hierarchic regression analysis. The findings show that, regardless of gender, Facebook ranked highest in the classification of students' purpose of Internet use; it was also found that females mainly used the Internet for communication, whereas males were more interested in playing online games and reading newspapers and magazines. The results of hierarchic regression analysis indicated that the significant predictors of the internet addiction were the presence of Internet access at home, gender, and family income levels.