In 1947, Pisani was appointed chief officer of Haute-Marne, and in 1954 was elected senator, a position he served until 1961. From 1961-1966, Pisani held the office of Minister for Agriculture of France.
In 1967, he held a seat in the National Assembly as a deputy of the Maine-and-Loire, and from 1974 to 1981, Pisani held office as a socialist senator of Haute-Marne. In 1985 he was elected Minister in charge of New Caledonia.
From 1988 to 1995, Edgar Pisani was the president of the Institute of the Arab World (L'Institut du Monde Arabe), and in 1992 was elected by the UN General Assembly to occupy a seat on the Economic and Social Council. The Council coordinates the work of the 14 UN specialized agencies, 10 functional commissions, and five regional commissions; receives reports from 11 UN funds and programmes; and issues policy recommendations to the UN system and to Member States.
Now in retirement, Edgar Pisani once served as the president of the International Centre for Advanced Mediterranean Agronomic Studies. The Centre is an intergovernmental organisation supporting development in the Mediterranean, with the objective of providing economic and technical education and promoting the spirit of international co-operation between agricultural supervisors in Mediterranean countries.