This contribution puts forward an explorative account of the Swiss political parties’ presence on Twitter. Social media in general, and the Twitter micro-blogging service more in particular, have recently received a lot of attention by social science scholars and political observers, yet the validity of these data sources is heavily disputed. This study takes one step back and tries to establish an empirically testable data base for party communication on Twitter in Switzerland, a context which is not well studied so far. More precisely, this study serves two main purposes. First, the representativeness of Swiss party accounts on Twitter in terms ideology, location and language is assessed. Subsequently, social network analysis is applied to provide evidence on the degree of political homophily and party elite dominance. It can be shown that the Swiss partisan Twitter sphere is systematically biased towards the political left and urban areas. Furthermore, it is revealed that Twitter users are separated into a handful of highly networked actors and many peripheral ones. These results have direct implications for social scientists and political observers interested in harnessing reliable social media data.