Ultrathin films of rare earth arachidates were prepared by the standard Langmuir-Blodgett technique and analyzed by various surface-sensitive experimental methods. In-situ investigations on the subphase provided information about the dependence of the film stability of the counter ion used. In general the stability increases with its atomic number. Heavy ion induced desorption mass spectrometry and photoelectron spectroscopy confirm the formation of trivalent rare earth arachidate salts. The surface morphology was examined by atomic force microscopy which demonstrates that these films have good transfer properties on gold/silicon substrates.