We have observed infrared active Nd 3 + ion crystal-field (CF) excitations as a function of temperature in Nd 2 CuO 4 single crystals. The detected absorption bands allowed to determine 23 excited CF levels of the 4 I term. Using these levels, a set of the parameters of the CF Hamiltonian has been calculated confirming the one determined previously by Raman measurements. CF excitations of Nd 3 + ions, in inequivalent sites, have also been detected in as-grown single crystals and associated with two different types of defects.