A new phenomenon, which increasingly rises among the young generation all over the world, is Internet addiction. Information and communication technology (ICT) has a major influence not only on individual sectors of the national economy (services, industry, agriculture, etc.), but also on free time activities and interests of the young generation. ICT-related free time activities of the young generation have notably changed over the last decade (Slovakia was connected to the Internet in November 1992). The aim of the research was to determine the symptoms of Internet addiction in Slovak secondary school students, i.e. to detect significant differences between the following: a personality trait – addiction, addiction – age, addiction – a place of residence, etc. The standardized questionnaire was used in all regions of Slovakia. We collected data by means of an online questionnaire over the period of more than six months. The research results show that female have more potential to become addicted than male, which could be caused by feelings and sadness (