Despite evidence that United Nations peacekeeping is a cost-effective tool for addressing civil and interstate conflict, it has consistently experienced financial shortfalls as member states neglect to pay their dues. To enable investigation into the dynamics of peacekeeping support, we present newly collected data on all member-state financial contributions to all UN peacekeeping operations from 1990 to 2010. The data also include dues assessed by the UN to gauge the extent to which states fall short of what they owe. We show that financial shortfalls are widespread and vary across both missions and contributors. The data offer opportunities to understand patterns of financial support for peacekeeping across states, missions, and time, and can ultimately provide insight into the factors that lead states to support international institutions and public goods. We illustrate how scholars can use the data with an analysis of the factors that drive states to meet their financial commitments. We find that wealthier states, those more engaged in global trade, democracies, and those that also contribute personnel to peacekeeping operations are the most likely to pay their dues. Conversely, the United States and countries in the Americas, Africa, and Asia are more likely to shirk part or all of their financial obligations in a given year.