In November 1990 ICMA was granted affiliate membership of the Madrid-based International Organisation of Securities Commissions (IOSCO) whose principal members comprise the statutory or governmental regulatory authorities supervising the securities, futures and options markets in most jurisdictions worldwide.

As an affiliate member, ICMA is a member of IOSCO's SRO Consultative Committee.

In September 1991 ICMA became a member of the International Councils of Securities Associations (ICSA), a forum for non-governmental regulatory organisations, whose objectives are to aid and encourage the sound growth of the international capital markets by promoting and encouraging harmonisation in the procedures and regulations of those markets.

ICSA currently comprises 14 self-regulatory organisations and trade associations representing investment firms and dealers active in the international capital markets.