The paper deals with differences in the Internet use as a means of communication in the Czech Republic from the point of view of Internet users' gender and age. It aims at depicting the differences in pretending to have a different identity in the virtual environment. The presented questions were included in a questionnaire survey carried out within the framework of the international World Internet Project research. The survey sampled 1,832 respondents aged 12 years or more. It has been revealed that, from the point of view of Internet preference as a means of communication, there are only statistically insignificant differences between men and women; however, it is men who tend to claim, more often than women, to be more open on the Internet than in the real world. Furthermore, they also admit pretending a new identity. There have been large differences in virtual communication preference according to the respondents' age: adolescents and young people tend to prefer substantially more often the Internet as a means of communication than older people. At the same time, it is adolescents rather than adults who tend to experiment more with their identity in the virtual environment.