Office of Internal Oversight Services
Legal statusActive
Fatoumata Ndiaye
Parent organization
United Nations Secretariat
  • Inspection & Evaluation Division
  • Internal Audit Division
  • Investigations Division

The United Nations Office of Internal Oversight Services (OIOS) is an independent office in the United Nations Secretariat whose mandate is to "assist the Secretary-General in fulfilling his internal oversight responsibilities in respect of the resources and staff of the Organization."[1] Specifically, activities include internal audit, investigation, monitoring, evaluation, inspection, reporting and support services to the United Nations Secretariat.[2]

Its intended and mandated function is similar to many national government audit organisations, like the Government Accountability Office in the United States. It reports not only to the General Assembly, but also to the Secretary-General.

The current head of the OIOS, Under-Secretary-General Fatoumata Ndiaye[3] of Senegal, was appointed as Under-Secretary-General for Internal Oversight Services for a five-year term starting on 17 October 2019, succeeding Heidi Mendoza of the Philippines.[4]

The office was established in 1994 at the insistence of the United States that the UN take steps to curb waste and corruption, although there are some doubts concerning its effectiveness.[5] Its first head was Under-Secretary-General Karl Theodor Paschke.

Role and function

According to its website:

The Office submits reports to the Secretary-General that provide insight into the effective utilization of the resources of the Organization and the protection of its assets and also makes these reports available to the General Assembly. OIOS adds value by providing world-wide audit, investigation, inspection, programme monitoring, evaluation and consulting services to the United Nations Secretariat and a wide range of United Nations operational funds, programmes and tribunals. OIOS sees itself as an agent of change, committed to help client departments and offices bring about responsible administration of resources and a culture of accountability, transparency, results-orientation and risk awareness.


# Portrait Under-Secretary-General Dates in office Nationality

Karl Theodor Paschke 1 January 1994 – 31 December 1999 Germany Germany
2 Dileep Nair 24 April 2000 – 23 April 2005 Singapore Singapore
3 Inga-Britt Ahlenius 15 July 2005 – 14 July 2010 Sweden Sweden
4 Carman Lapointe 14 September 2010 – 6 October 2015 Canada Canada
5 Heidi Mendoza 15 November 2015[4] – 17 October 2019 Philippines Philippines
6 Fatoumata Ndiaye 17 October 2019[3] – Incumbent  Senegal


  1. ^ "Review of the implementation of General Assembly resolutions 48/218 B, 54/244 and 59/272" (PDF). UN. 5 May 2010. p. 1. Retrieved 16 March 2014.
  2. ^ "Activities and functions of OIOS". UN. Retrieved 16 March 2014.
  3. ^ a b "Fatoumata Ndiaye Under-Secretary-General for Internal Oversight Services". UN Office of Internal Oversight Services. 17 October 2019. Archived from the original on 22 August 2020.
  4. ^ a b Calleja, Niña P. (15 October 2015). "UN General Assembly OKs Heidi Mendoza's appointment". Philippine Daily Inquirer. Retrieved 29 October 2015.
  5. ^ Lynch, Colum (26 August 2016). "The U.N.'s Investigation Wars". Foreign Policy. Graham Holdings Company. Retrieved 18 March 2018. But the exchange with Malcorra exposed roiling turmoil at the core of a long-beleaguered U.N. department responsible for preventing fraud and waste in an organization that spends billions of dollars each year and conducts peacekeeping missions in fragile countries around the world.