alpha- and beta-Cyclodextrins cavity inclusion constants (K-i) were determined for a series of benzaldehydes and acetophenones by using two different methods: Benesi-Hildebrand (BH) UV/vis spectroscopic method and electrochemical current (EC) method, determined by cyclic voltammetry. The values determined in the group of benzaldehydes varied from 322 +/- 27 to 5688 +/- 317 mol(-1) dm(3) for UV/vis method, and 342 +/- 19 to 7386 +/- 142 mol(-1) dm(3) for EC method. The values determined in the group of acetophenones varied from 2201 +/- 88 to 9125 +/- 251 mol(-1) dm(3) for UV/vis method, and 1473 +/- 33 to 7555 +/- 187 mol(-1) dm(3) for EC method. The equilibrium time estimated for UV/vis spectroscopic (BH) method was 240 min and for the cyclic voltammetry (EC) method was 310 min. Notably, despite their limitations, both methods were suitable and reliable for inclusion constant measurement, if the equilibrium time of the system is well established. (C) 2010 Elsevier Ltd. All rights reserved.