In this paper we report on measurements of K alpha(1), K alpha(2), K beta(1), and K beta(2)' X-ray production cross sections and K shell fluorescence yields for 21 high atomic number elements. The targets were irradiated with gamma-photons at 123.6 keV from Co-57 annular source. The K X-rays from different targets were detected using a high resolution Si(Li) semiconductor detector. The measured K X-ray production cross sections were compared with calculated theoretical values. Similarly, the measured K shell fluorescence yields were compared with the experimental and theoretical data in literature. The results have been plotted versus atomic number. (c) 2006 Elsevier B.V. All rights reserved.