Inclusion complexes of ketoconazole (KT) with α-, β-cyclodextrin (CD) and dimethyl-β-cyclodextrin (DMβCD) in a molar ratio of 1:2 were prepared by freeze-drying and solvent evaporation methods. The interactions of KT with α-CD, β-CD and DMβCD in aqueous solution and in solid state were investigated by solubility study, infrared (IR) spectroscopy and differential scanning calorimetry (DSC). The stability constant of KT-DMβCD inclusion complex (IC) was found to be the largest among three inclusion complexes. Clear differences in IR spectra and DSC curves were observed between inclusion complexes and physical mixtures (PM) of KT-CDs. It was also shown by IR spectra and DSC curves that solvent evaporation method might be superior to the freeze-drying method in preparing the inclusion complexes of KT-CDs. The dissolution rate of KT was markedly increased by inclusion complex formation with CDs in the buffer solution at pH 4.0 and pH 6.8. The mean dissolution time (MDT, min), which represents the rapidity of dissolution, was in the order of KT-DMβCD IC (3.20) < KT-β-CD IC (4.36) < KT-α-CD IC (6.99) < KT-α-CD PM (17.46) < KT-β-CD PM (19.36) < KT-DMβCD PM (28.53). The dissolution rates of KT-CD ICsprepared by solvent evaporation method were faster than those of KT-CD ICs prepared by freeze-drying method.