Internal oversight

The Office of Internal Oversight Services (OIOS) is the internal oversight body of the United Nations (UN).  The Office assists the Secretary-General in fulfilling his oversight responsibilities in respect of the resources and staff of the Organization through the provision of internal audit, investigation, inspection and evaluation services. 

The mandate of OIOS is derived from relevant General Assembly resolutions and decisions, including founding resolution 48/218 B of 29 July 1994.

The Office exercises operational independence under the authority of the Secretary-General in the conduct of its duties and, in accordance with Article 97 of the Charter, has the authority to initiate, carry out and report on any action which it considers necessary to fulfil its responsibilities. 

The OIOS vision is a strong and accountable United Nations, fortified by world-class internal oversight. Our mission is to deliver objective oversight results that make a difference


Our strategic priorities

The Office adopts a risk-based approach to the planning of its work, consulting with senior management (and other oversight bodies) to ensure that its activities focus on those areas of strategic importance or significant risk to the Organization and its mandates and goals.

For example, one area of priority focus for the Office has been organizational culture, particularly given its importance to the implementation of the Secretary-General’s reforms. The programme of work includes assignments that are either primarily focused on, or include within their scope, examination of questions related to organizational culture and its impact on the control environment, risk management, achievement of results, and misconduct within the Organization.

Similarly, the Office has continued to provide assessments, advice and recommendations to those entities that perform centralized, business-enabling functions, thus contributing to strengthening the “second line of defence” within the Organization.

The Office regularly communicates with management, and the respective audit committees, on the status of implementation of its work plan and on its assessment of risk and areas of focus.


Our principles

The Office integrates a gender perspective in its operational activities, deliverables and results and is also committed to pursuing the goals of inclusion and empowerment of persons with disabilities and their rights, well-being and perspectives. The Office is also committed to environmental sustainability and reducing the environmental impact of its operations. 

Through its audit, inspection and evaluation activities, the Office will also enhance its support for ensuring that United Nations entities are accountable for their performance with regard to gender diversity, the inclusion of persons with disabilities and their human rights, and environmental stewardship.


Our activities

Internal Audit


Inspection & Evaluation



The internal auditing function is an independent and objective assurance and advisory activity designed to add value and improve the UN's operations. Internal audits help the UN to accomplish its objectives by bringing a systematic, disciplined approach to assess and improve the effectiveness of governance, risk management and control processes.


The Inspection and Evaluation Division conducts independent assessments of UN work to help deliver better results, enable managers to learn and adapt, and provide public accountability for activities and resources. Our evaluations cover the normative, programmatic, and operational areas of the Organization.


We aim to foster greater transparency and accountability within the Organization. The Investigations Division strives to protect the human and financial resources of the UN by investigating, fraud, corruption, sexual exploitation and abuse and other misconduct in the workplace

Highlight of recent work

Report on the activities of the Office of Internal Oversight Services
9 August 2023

The report provides an overview of OIOS activities during the period from 1 July 2021 to 30 June 2023. 

During the reporting period, OIOS issued 240 oversight reports (excluding those relating to peace operations), including 7 reports to the General Assembly. The reports included 626 recommendations designed to improve risk management, governance and operations, of which 7 were classified as critical. 

The financial implications of the recommendations issued by the Office during the period led to quantifiable and directly attributable savings and recoveries amounting to $1.2million. 

The addendum to the report provides an analysis of the status of implementation of the recommendations and a list of reports issued.

Our people

Statistics as at 31 August 2023

OIOS impact | 2022/23 results

During 2022/23, OIOS issued 1,101 recommendations, contained in 414 reports, including those pertaining to peace operations.

99% of the 1,101 recommendations issued were accepted.