The stability constants (K), standard free energy (ΔG o ), enthalpy (ΔH o ), and entropy changes (ΔS o ) for the complexation of pyrogallol[4]arenes with ammonium cations of different size and shape have been determined in ethanol at 298K by isothermal titration calorimetry. The trends observed in the thermodynamic parameters for 1:1 and/or 1:2 host–guest complexation correspond to the systematic structural changes of the guest molecules. On the basis of the results obtained we compare the complexation properties with two other resorcin[4]arenes and discuss the thermodynamic aspects of this supramolecular host–guest interactions.