The International Organizations of Securities Commissions was set up as a legal non-profitable entity under Canadian law in 1983. The present organization has been a result of the change that took place in the Interamerican Supervisors and Regulators Securities Association.  Once this organization was established in Spain, the Spanish Government gave IOSCO the legal right of  a public interest association. The CNMV has been representing Spain as an ordinary member of the organization since 1990.

The IOSCO's aims are the following: work together for the promotion of high regulation standards to maintain fair, efficient and solid markets; exchange of information among their members on their experience with the purpose of promoting the development of the national markets; join endeavours to settle standards and an effective supervision on international securities transactions; and provide mutual assistance with the purpose of promoting the integrity of the markets with a strict standards practice and an effective inspection of infringements committed by the market participants.

The IOSCO's recommendations, in addition to the Principles issued by the equivalent Committees for banking and insurance areas (The Basel Committee on Banking Supervision (BCBS) and International Association of Insurance Supervisors (IASB) respectively), are taken into account by the International Monetary Fund (IMF) and the World Bank (WB) in their Financial Systems Assessments Programmes. (FSAPs)

There are three types of members ordinary members (authorities), associated members (other authorities with powers in securities field), and affiliated members (generally self-regulated organizations).

IOSCO has the following structure: a Presidents Committee (attended by the presidents of the organizations members -except affiliated-) that  holds  an annual assembly, and a Executive Committee formed by the 19 elected members. The Executive Committee has two specialised working committees, the Technical Committee and the Emerging Markets Committee. Besides, there are four regional committees: the African-Middle East, the Asian-Pacific, the European and the Interamerican. The CNMV takes part in the Executive, Technical and  the European Committees. Spain has, since 2007, been an associated member of COSRA (Council of Securities Regulators of the Americas) which is an association (different from IOSCO) composed by all the countries of America that meets on the occasion of the Interamerican Committee meetings.

The Technical Committee's work is developed through specific mandates given to the six permanent working groups (called Standing Committees) and, in some cases, through temporal working groups (called Task Force or Project Teams). The Standing Committees (SCs), numbered 1 to 5, deal with the following five major functional subject areas: SC 1 (accounting, auditing, information disclosure and IRFS), SC 2 (Regulation of secondary markets), SC 3 (regulation of market intermediaries), SC 4 (cooperation, enforcement and exchange of information), SC 5 (Collective investment schemes ) and SC 6 (credit rating agencies). The temporal groups have been set up to issue reports on unregulated financial products and markets, financial unregulated entities, short selling, commodity futures markets, supervisory cooperation and sovereign wealth funds.
There are also some working groups created directly by the Executive Committee and depending directly on it. They are named strategic direction, screening verification, MMOU monitoring multilateral memorandum of understanding, and implementation.