American Presbyterians had undertaken mission work in Europe earlier in the 20th century -- founding the American Church in Paris, the American Church in Berlin, and contributing to relief during the famine in Russia -- but only began a continent-scale effort in the mid-1940s. Responding to the World Council of Churches' appeal for an ecumenical reconstruction effort, the Presbyterian Church in the U.S.A. established contact with CIMADE, the Comité inter-mouvements auprès des evacuées, which had been sheltering and feeding refugees in France since 1940. Benjamin Bush was sent to Geneva as PCUSA mission executive for Europe in 1945 with the initial task of serving refugees, reconstructing church buildings, and distributing aid. By 1950 there were twelve PCUSA fraternal workers in Europe, including at Conderque, the Ruhr Valley, and Le Havre and Mainz.

As the physical landscape of the continent and the bodily condition of its people began to recover, the Geneva office tailored its work to the care of Protestant pastors and to the establishment and support of interchurch bodies. In addition to contributing to the first ecumenical conference of ministers in Yugoslavia, held at Novi Vrbas in 1948, the PCUSA Europe Mission supported ECLOF -- the Ecumenical Church Loan Fund; built the Christian conference center Foyer John Knox; and contributed to the ongoing relief and reconstruction work of the World Council of Churches Division of Inter-Church Aid, Refugee, and World Service (DICARWS). In this capacity the PCUSA Europe Mission pivoted from relief of Europeans -- as the economic engine sparked by the Marshall Plan turned over -- to relief of migrants to Europe and the distribution of aid from European churches to Africa and the Middle East. The Mission also arranged for and supported terms of study abroad spent at Protestant theological seminaries in Europe by young African theologians. Until 1989 the Mission served as a clearinghouse for correspondence from ministers laboring secretly in the officially-atheist regimes of the Soviet bloc. After the fall of the Soviet Union, the urgency of maintaining a PC(USA) footprint in Geneva declined, and the area representative for Europe was removed to national headquarters in Louisville.