Thermodynamic partition functions between water and heptane of the square-planar palladium bis-acetylacetonate and bis-2,4-hexanedionate were determined and compared with partition functions of the corresponding tetrahedral complexes of beryllium. Higher partition coefficients, less positive enthalpy and entropy of partition and lower salting-out coefficients of palladium complexes point to their less hydrophilic character. A plausible explanation is the hindered access of water molecules to ligand oxygen atoms in square-planar complexes.