The Second International Conference on Nuclidic Masses was held in Vienna, Austria, July 15-19, 1963, using facilities of the International Atomic Energy Agency. This was the third conference in the general area of nuclidic masses in recent years. The first, a symposium held at the Max Planck Institut fur Chemie in 1956, was international in character but not in name. The First International Conference on Nuclidic Masses was held at McMaster University in September of 1960 in conjunction with and shortly after the meeting of the General Assembly of the International Union of Pure and Applied Physics and the Kingston Conference on Nuclear Structure. The Second International Conference on Nuclidic Masses was held under the sponsorship of the International Union of Pure and Applied Physics and the Nuclear Science Committee of the National Academy of Sciences-National Research Council of the United States. Financial support for the conference came from the United Nations Educational, Scientific, and Cultural Organization. The conference committee was made up of the following individuals: Chairman: J. H. E. MATTAUCH General Secretary: H. E. DUCKWORTH Local Secretary: F. P. VIEHBOCK w. W. BUECHNER B. GROSS E. R. COHEN M. J. HIGATSBERGER A. DE SHALIT A. O. C. NIER J. W. M. DuMoND H. H. STAUB B. S. DZHELEPOV D. M. VAN PATTER A. H.