A method to obtain high sensitivity and accuracy for nondestructive analysis of gold ore is proposed. The applied technique is energy-dispersive X-ray fluorescence, using a Co-57 radioisotope source to excite gold K X-rays in the sample, and a high-purity Ge (HPGe) detector with a range of energies from 1 keV to 4 MeV. The use of radioisotope sources and K X-rays gives some advantages in comparison with other analytical techniques and the usual tube excitation L X-ray analysis: the high sensitivity to concentrations of 1 ppm, the absence of interferences from other elements present in the matrix, and the possibility of performing fast and economical nondestructive analyses of large samples.