The f(12), f(13) and f(23) Coster-Kronig (CK) transitions (that is L-1 --> L-2, L-1 --> L-3 and L-2 --> L-3 transitions) in Hg and Bi in molecules were studied at 59.5 keV excitation energy using an Si(Li) detector. A change in the CK transition probabilities was observed for different molecules. The change in the values for Hg compounds were greater than those for Bi compounds. Because we did not have pure Bi in the laboratory and also were not able to have specimen preparation conditions for pure Hg, we did not obtain experimental values for elemental Bi and Hg. Copyright (C) 2002 John Wiley Sons, Ltd