Although diverse political news has been recognized as a requirement for a well-functioning democracy, longitudinal research into this topic is sparse. In this article, we analyse the development of diversity in election coverage in the Netherlands between 1994 and 2012. We distinguish between diversity for party and issue coverage, and look at differences between diversity in newspapers and television news. Results show that news diversity varies over time. Diversity for party types increased over time. We found no clear trend for diversity of issue dimensions. Compared to newspapers, television news is more diverse for party types but less diverse on issue dimensions. The question concerning whether these findings are an indicator of structural bias is discussed.