Equilibrium constants and standard molar enthalpies of reaction have been determined by titration calorimetry for a series of cyclohexane derivatives (cis-1,2-cyclohexanediol, cis,cis-1,3,5-cyclohexanetriol, trans-1,2-cyclohexanediol, cyclohexanol, cyclohexanone, 2-methylcyclohexanone, 2,5-piperazinedione, and delta-valerolactam) with alpha-cyclodextrin and beta-cyclodextrin. For the reactions involving cyclohexanol, standard molar heat-capacity changes were also determined from calorimetric measurements performed at several temperatures. The equilibrium constants for the reactions of these substances with beta-cyclodextrin are in all cases larger than those for the corresponding reactions with alpha-cyclodextrin. It was also found that the equilibrium constants for the reactions of these substances with gamma-cyclodextrin were too small (<4) to measure with this method. An important feature of these reactions is that while the standard molar enthalpies of reaction are approximately the same for both cyclodextrins, the standard molar entropy changes for the reactions of these substances with beta-cyclodextrin are substantially more positive than for the reactions with alpha-cyclodextrin. The hydrophilic nature of the groups on the cyclohexane ring as well as steric effects was found to influence the thermodynamics of these reactions. The standard molar enthalpy of transfer of the cyclohexane derivatives from the alpha-cyclodextrin complex to the beta-cyclodextrin complex was found to be a linear function of the standard molar entropy change for this same transfer reaction. NMR results indicate that while the proximity of these cyclohexane derivatives to the walls of the alpha-cyclodextrin and that to the walls of the beta-cyclodextrin are comparable, the cyclohexane derivatives penetrate deeper into the larger beta-cyclodextrin cavity than into the smaller alpha-cyclodextrin cavity.