In the present work, a method for the simultaneous enantioselective separation of bupropion (BUP) and hydroxybupropion (HBUP) by capillary electrophoresis (CE) was developed. After the optimization process, the best results found were: 75 mmol L-1 phosphate BGE at pH 7.0; 4.0 mg mL(-1) for the sulfated-beta-cyclodextrin (S-beta-CD). This experimental protocol provided the best resolution values (Rs(1) = 2.06, Rs(2) = 5.62 and Rs(3) = 6.68). From the theoretical calculations, based on the energetic and structural obtained results, it was possible to point out, on the molecular level, the migration order of BUP and HBUP enantiomers.