In recent years, a number of studies have suggested a positive linkage between public service broad- casting and public knowledge about current affairs. Most studies are, however, based on aggregate, cross-sectional data. On the individual level they fall short of establishing any causal linkage between TV news exposure and public knowledge. In addition, studies which investigate whether the intensity of the political information environment matters for learning effects from watching TV news, are missing. Against this background, this study compares knowledge effects from watch- ing public service and commercial TV news in three contexts that vary in the intensity of the political information environment: a national election campaign, a European parliamentary election cam- paign and a non-election period. Among other things, the results show stronger knowledge effects from watching public service than commercial TV news.