Internationally, Rissho Kosei-kai is active in working with the International Association for Religious Freedom (IARF), the World Conference of Religions for Peace (WCRP), and the Asian Conference on Religion and Peace (ACRP), and also closely cooperates with the Vatican, the World Council of Churches (WCC), the Unitarian Universalist Association (UUA), and other religious organizations.

In Japan, Rissho Kosei-kai has been active in Shinshuren (Federation of New Religious Organizations of Japan) since 1951. Sixty-six religious organizations join with it and endeavor to achieve four main goals: implementation of interreligious cooperation, defense of religious freedom, separation of state and religion, and promotion of a religious spirit among people. In addition, Shinshuren has been taking steady steps for the abolition of nuclear weapons, the defense of human rights, and to find solutions to environmental problems.

Rissho Kosei-kai churches conduct interfaith dialogue and cooperation activities in many parts of the country throughout the year, as well as during the important Week of Prayer for World Peace in October. For example, in Setagaya, one of the 23 wards of Tokyo, the Setagaya Interreligious Association, which consists of 21 religious groups from Buddhism, Christianity, Islam, and Shinto, was established ten years ago at the initiative of the Setagaya Rissho Kosei-kai Church. On November 25, 2000, more than a thousand citizens came together at the association's Ninth Gathering to Pray for World Peace at the Hitomi Memorial Hall of Showa Women's College in Setagaya.