This study investigates gender differences in Internet use by Greek high school pupils within school and out of school environments. A sample of 340 pupils (170 boys and 170 girls), aged 12-16 years, completed a written questionnaire on their attainability, location, frequency and purposes of Internet access. The data analysis showed that more pupils use the Internet outside school (at home, in Internet cafes) than within school and that boys have more opportunities to access the Internet. Both inside and outside school, pupils' favourite Internet activities relate to information gathering for personal purposes and to entertainment. Boys use the Internet for entertainment and Web page creation more than girls do, whereas no other significant gender differences were noted regarding pupils' other Internet activities, such as communication via e-mail, chat or videoconferencing, Web surfing and information search for personal or school purposes.