This article investigates whether agenda-setting relations between newspapers and political parties are influenced by political parallelism. Our case is the Netherlands, a country characterized by high levels of journalistic professionalization and independent media. We focus on newspaper coverage and oral parliamentary questions and use time series analysis to inspect influence both of parliament on newspapers and of newspapers on parliament. The results show that parties respond only to issues raised in newspapers their voters read, and that newspapers only respond to the agenda of parties their readers vote for. This demonstrates that even in mediatized, professionalized media contexts, parallelism is still of importance to understand the relationship between media and politics.