Since 1970, recognized political parties in the Canadian House of Commons have received funding for caucus research offices. Staffed by political partisans, research offices provide policy, communications, research and administrative support to party leaders and their parliamentary caucuses. This research note examines the evolving organization, work and function of these offices. It demonstrates, first, that the tendency towards centralization, evident in Canadian politics for decades, is clearly reflected in research offices’ primary support for leaders rather than individual caucus members. Second, research offices are integral to parties’ strategic communications and marketing efforts, and this, especially in government, often eclipses their policy contribution. Third, while the government party views caucus researchers as a useful supplement to public service and ministerial office resources, opposition parties rely heavily on their caucus research offices as their dominant source of staff capacity.