The following properties of mixtures of the butanols with cyclohexane were measured over the whole range of composition: 1-butanol+cyclohexane and 2-butanol+cyclohexane; excess enthalpies at 15, 25, 35 and 45°C, excess volumes at 25 and 45°C, activity coefficients and excess Gibbs free energies at 45°C. 2-Methylpropan-2-ol (tertiary butanol)+cyclohexane; excess enthalpies at 26, 35, and 45°C, excess volumes at 26 and 45°C, activity coefficients and excess Gibbs free energies at 45°C. From these data, activity coefficients at the temperatures of the excess enthalpy measurements below 45°C have been computed, as a source of test data for models of alcohol association through hydrogen bonding.