Gold-198 with a specific activity of 370 Ci/g and containing <0.1% 199Au was produced by the epithermal neutron-capture reaction, 197Au(n,γ) 198Au. The secondary neutron-capture reaction, 198Au(n,γ)199Au, was greatly reduced by a thermal-neutron absorber—a cadmium capsule in which the samples of gold foil and gold-aluminum alloy were irradiated. High-specific-activity 198Au with <0.1% 199Au is especially useful for medical purposes.