Following nine years of service in the army, Riad joined the Ministry of Foreign Affairs in 1952 and quickly climbed through the diplomatic ranks.

In 1967, Riad worked with his colleague and friend, Ambassador Charles W. Yost, in an effort to find a solution before the outbreak of war.

He was elected Secretary General of the League of Arab States in 1972, succeeding Abdul Khalek Hassouna, also an Egyptian.

Riad relinquished the League of Arab States post in 1979 at the height of a crisis caused by Egypt's signing a peace treaty with Israel.

His most prominent book titled "The Struggle for Peace in the Middle East" was translated to English and published in London, England 1982 (ISBN 0 7043 2297 8).