ICSID is an autonomous international institution established under the Convention on the Settlement of Investment Disputes between States and Nationals of Other States (the ICSID or the Washington Convention) with over one hundred and forty member States. The Convention sets forth ICSID's mandate, organization and core functions. The primary purpose of ICSID is to provide facilities for conciliation and arbitration of international investment disputes.

The ICSID Convention is a multilateral treaty formulated by the Executive Directors of the International Bank for Reconstruction and Development (the World Bank). It was opened for signature on March 18, 1965 and entered into force on October 14, 1966.

The Convention sought to remove major impediments to the free international flows of private investment posed by non-commercial risks and the absence of specialized international methods for investment dispute settlement. ICSID was created by the Convention as an impartial international forum providing facilities for the resolution of legal disputes between eligible parties, through conciliation or arbitration procedures. Recourse to the ICSID facilities is always subject to the parties' consent.

As evidenced by its large membership, considerable caseload, and by the numerous references to its arbitration facilities in investment treaties and laws, ICSID plays an important role in the field of international investment and economic development.

Today, ICSID is considered to be the leading international arbitration institution devoted to investor-State dispute settlement.