The inelastic mean free path of electrons (IMFP) can be determined from the only experimental method, i.e. from the elastic peak electron spectroscopy (EPES). In this method, experimentally determined ratios of elastically backscattered electrons from test surfaces and from a reference material are compared with the values evaluated from Monte Carlo calculations. The paper is dealing with the experimental determination of the IMFP in GaAs, GaSb, InP and InSb within the 50-2000 eV range. The data have been recorded using the DCMA-PHI15255G spectrometer and compared with the theoretical data available.