Ligand field splitting energies of lanthanides Ln(3+) (Ln = from Ce to Yb) in octahedral environment are calculated using the Hohenberg-Kohn theorems based orbital-free embedding formalism. The lanthanide cation is described at orbital level whereas its environment is represented by means of an additional term in the Kohn-Sham-like one-electron equations expressed as an explicit functional of two electron densities: that of the cation and that of the ligands. The calculated splitting energies, which are in good agreement with the ones derived from experiment, are attributed to two main factors: (i) polarization of the electron density of the ligands, and; (ii) ion-ligand Pauli repulsion. (C) 2004 Elsevier B.V. All rights reserved.