The Expediency Discernment Council of the System[1] (Persian: مجمع تشخیص مصلحت نظام Majma'-e Tašxis-e Maslahat-e Nezâm) is an administrative assembly of Iran appointed by the Supreme Leader[2] and was created upon the revision to the Constitution on 6 February 1988.

[3] It was originally set up to resolve differences or conflicts between the Majlis and the Guardian Council, but "its true power lies more in its advisory role to the Supreme Leader."

According to Hooman Majd, the Leader "delegated some of his own authority to the council—granting it supervisory powers over all branches of the government" following President Mahmoud Ahmadinejad's election in 2005.

[5] By 1987, the legislative process as well as the country's long-term policy formation had come to a standstill due to the doctrinal conflict between radical factions of the Islamic Consultative Assembly and the Guardian Council, which officials described as coercive at the time.

Consultations in February the following year led to Ayatollah Khomeini ordering the appointment of a 13-member council that was given legislative authority: it could pass temporary laws (effective for three-year periods).

Article 112 of Iran's Constitution states the EDC will be convened by the Supreme Leader to determine expedience cases where the Guardian Council finds an Islamic Consultative Assembly decision against the principles of religious law or the constitution, and where the Consultative Assembly is unable to satisfy the Guardian Council in view of the expedience of the Islamic Republic of Iran.

Domestic and foreign policies of the regime are determined only after consultation with the Expediency Council, according to article 110 of the Constitution (with oversight of the Supreme Leader).

The Expediency Discernment Council can advise the faghih on policy and strategy (in accordance to article 111 of the Constitution), and despite not being part of the legislative branch, it can remove parliamentary powers.

Conservatives did not want to lose control of the Guardian Council, dreading president Mohammad Khatami and reformist allies would push through political and social reforms.