>Effective activation resonance integrals for thin and thick foils in an isotropic neutron flux were measured by a cadmium ratio method. Gold was used as a standard. Values obtained for dilute resonance integrals in barns, not including 1/v capture, were: Au/sup 197/, 1390 plus or minus 40 (Reference); U/ sup 238/ capture, 280 plus or minus 10; Cu/sup 63/, 3.17 plus or minus 0.18; Cu/sup 65/, 1.39 plus or minus 0.22; Mo/sup 98/, 9.9 plus or minus 1.1; Mo/sup 100/, 4.06 plus or minus 0.23; W/sup 186/, 476 plus or minus 50; and Na/sup 23/ , 0.075 plus or minus 0.010. Dilute resonance integrals including 1/v capture above 0.60 ev were: U/sup 235/ fission, 263 plus or minus 9 and In is, 3200 plus or minus 100. These resonance integrals and the measured resonance flux self-shielding factors were generally in good agreement with calculations. However, the two isotopes of molybdenum appeared to have major contributions to their resonance integrals from nontabulated resonances. Special methods used with various foils are described. (auth)