Entropies of fusion and vaporisation of a variety of elements and compounds have been derived from literature data. Fusion entropies range from low values for metals and certain cyclic hydrocarbons (e. g., cyclopentane) through modest values for salts to high values for materials undergoing drastic rearrangement or disentanglement such as aluminium chloride and n-alkanes. Entropies of vaporisation for most substances are close to the Trouton's Law value of similar to 100 J . deg.(-1) . mol(-1), with low values for species which associate on boiling (e. g., acetic acid) and higher values signifying simple dissociation (e. g., nitrogen tetroxide) or total decomposition (e. g., some ionic liquids). The nature of inorganic and semi-organic salts in all 3 phases is discussed. (C) 2013 Elsevier Ltd. All rights reserved.