Mayors for Peace, through close cooperation among the cities, strives to raise international public awareness regarding the need to abolish nuclear weapons and contributes to the realization of genuine and lasting world peace by working to eliminate starvation and poverty, assist refugees fleeing local conflict, support human rights, protect the environment and solve the other problems that threaten peaceful coexistence within the human family.

In August 1945, atomic bombs instantaneously reduced the cities of Hiroshima and Nagasaki to rubble, taking hundreds of thousands of precious lives. Today, more than sixty years after the war, thousands of citizens still suffer the devastating aftereffects of radiation and unfathomable emotional pain. To prevent any repetition of the A-bomb tragedy, the cities of Hiroshima and Nagasaki have continually sought to tell the world about the inhumane cruelty of nuclear weapons and have consistently urged that nuclear weapons be abolished.

On June 24, 1982, at the 2nd UN Special Session on Disarmament held at UN Headquarters in New York, then Mayor Takeshi Araki of Hiroshima proposed a new Program to Promote the Solidarity of Cities toward the Total Abolition of Nuclear Weapons. This proposal offered cities a way to transcend national borders and work together to press for nuclear abolition. Subsequently, the mayors of Hiroshima and Nagasaki called on mayors around the world to support this program.

In March 1990, the Mayors Conference was officially registered as a UN NGO related to the Department of Public Information. In May 1991, it became a Category II NGO (currently called a NGO in "Special Consultative Status") registered with the Economic and Social Council. Mayors for Peace is composed of cities around the world that have formally expressed support for the program Mayor Araki announced in 1982. As of October 1, 2010, membership stood at 4,207 cities in 144 countries and regions.