GIAO and CSGT models at Hartree-Fock and DFT/B3LYP levels of theory using different basis sets were employed for calculations of H-1 and C-13 NMR chemical shifts for para-X-substituted (X = H, CH3O and NO2) aromatic carbonyl compounds. For these compounds the best choice to evaluate theoretical chemical shifts is B3LYP/cc-pVDZ using CSGT model. (C) 2004 Elsevier B.V. All rights reserved.