The first part of the article deals with the definition of prevention, its purpose and inclusion into the health care and schools system,the work strategies of clinic and preventive branches.In the second part is put on on the history and possibilities of using and misusing the international computer network that concentrates on the primary antidrug prevention. In the third part there are several projects run at the Masaryk University mentioned that are dealing with Internet as a mean to communication and a source of information. The aim of the article is to encounter the teachers with significance of the prevention stages and to picture some new trends in solving the research goals in this specific field.