UN peacekeeping is highly cost-effective. The UN spends less per year on peacekeeping worldwide than the City of New York spends on the annual budget of its police department. In 1993, annual UN peacekeeping costs reached some $3.6 billion, reflecting the expense of massive operations in the former Yugoslavia and Somalia . By 1998, costs had dropped to just under $1 billion. With the resurgence of larger-scale operations, costs for UN peacekeeping rose again, and as of March 2006, the approved peacekeeping budget for the year from 1 July 2005 to 30 June 2006 was over $5 billion. This represented only 0.5% of global military spending. Peacekeeping is far cheaper than war.

All Member States are legally obliged to pay their share of peacekeeping costs under a formula that they themselves have established. Despite this legal obligation, Member States owed approximately $2.66 billion in current and back peacekeeping dues as of 31 January 2006

The top 10 providers of assessed contributions to UN peacekeeping operations were (as of 1 January 2006): the United States, Japan, Germany, the United Kingdom, France, Italy, Canada, Spain, China and the Netherlands.