The aim of the analysis is to present a preliminary typology as well as a genre and structural description of texts published on profiles of selected radio and TV stations on Twitter, a microblog platform. Conducting such an analysis seems purposeful due to the growing popularity of microblog portals in the mass media as well as the increasing number of users of such online platforms. The analysis regards in particular the genre and functional aspect of the posts published on the said platform. Content analysis enabled distinction of tweets characterised by a presentation & recommendation, information and phatic, interactive dominant. Genre, structural and discoursive references to paratextual genres (preview, teaser) as well as current affairs and news genres (newsflash) can be noticed among tweets. (Tł. Monika Czarnecka).