The challenge of a cathedral is very good for architectural inventiveness.

This included the design of the Edifício Copan (a large residential building in São Paulo) and a collaboration with Le Corbusier (and others) on the design of the United Nations Headquarters which engendered invitations to teach at Yale University and the Harvard Graduate School of Design. In 1963 he became an honorary member of the American Institute of Architects in the United States; the same year he received the Lenin Peace Prize from the USSR. During the military dictatorship of Brazil his office was raided and he was forced into exile in Europe.

In 1956 Niemeyer was invited by Brazil's new president Juscelino Kubitschek to design the civic buildings for Brazil's new capital which was to be built in the centre of the country far from any existing cities. His work especially on the Church of Saint Francis of Assisi received critical acclaim and drew Niemeyer international attention.