Calix[n]arenes have become very popular building blocks in supramolecular chemistry due to their unique molecular architecture suitable for the complexation of various guest molecules. These complexes are held together by simultaneous influence of weak non-covalent interactions, such as hydrogen bonds, electrostatic interactions, van der Waals interactions, hydrofobic effects, etc. Very recently, cation-p interactions have been recognised to contribute to the overall binding process. The role of these interactions in the complexation of Ag⁺ and pyridinium cations is discussed and exemplified by several suitably designed calix[4]arene-based receptors.