Abstract: A uniform-sized molecularly imprinted polymer for (S)-ibuprofen has been prepared by a multi-step swelling and thermal polymerization method using 4-vinylpyridine (4-VPY) and ethylene glycol dimethacrylate (EDMA) as a host functional monomer and cross-linker, respectively. The obtained (S)-ibuprofen imprinted 4-VPY-EDMA materials were evaluated using aqueous eluents by HPLC. Hydrophobic and hydrogen bonding interactions between ibuprofen enantiomers and 4-VPY-EDMA materials could play an important role in the retentivity and enantioselectivity. Further, partial resolution of the enantiomers of ibuprofen metabolites, 2-hydroxy- and 2- carboxyibuprofen, was attained with the (S)-ibuprofen imprinted 4- VPY-EDMA materials. (C) 1999 Elsevier Science BN. All rights reserved