The concept of internet addiction refers to the excessive use of internet which in turn causes various problems in individual, social and professional aspects. The aim of this study is to determine the relationship between depression and internet addiction in terms of grades, sex, the existence of internet connection at home and time spent on internet. The study used survey model. The study group consisted of 369 adolescents from three high schools of different socio-economic background. Data was collected by means of "Personal Information Form", "Internet Addiction Scale" and "Beck Depression Inventory". Arithmetic mean, standard deviation, independent sampling t test, ANOVA and Scheffe tests were performed on collected data. The results of the study show that the internet addiction and depression scores of the adolescents are low and the internet addiction levels of ninth and tenth grade students compared to the eleventh grade ones; of males with compared to females; of those having computer at home with compared to the ones having no internet at home and of the ones spending much more time on internet with compared to those spending less time have been found to be higher. No significant difference has been found between depression and internet addiction.