Plans for setting up an international center for theoretical physics at Trieste early in 1964 have been announced by the International Atomic Energy Agency. The proposed center has been under discussion by the IAEA General Conference and its Board of Governors since September 1960, and a series of studies were made with the help of theoretical physicists from many countries. The Italian government has offered to construct a new building and housing facilities, to provide staff services and fellowships, and to contribute $250 000 annually for five years. The IAEA will provide fellowships and professorships up to an annual value of $55 000 for four years and make additional contributions up to $110 000 in the same period. It was decided to establish the facility on a provisional basis and to evaluate its work after two years to determine the direction of future activity. A further review would be undertaken after four years to determine if it would be desirable to move the center to a developing country.