The influence of the synthetic macrocycle 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo [8.8.8]hexacosane on the intermolecular interactions of sodium taurodeoxycholate aqueous solutions has been investigated by cryoscopic, conductometric, and surface tension methods. The results show that the cryptand causes an appreciable shift of the critical micellar concentrations, toward the lower bile salt concentration. In addition, the complexing agent strongly affects the conductance and enhances the surfactant properties of the taurodeoxycholate. These features have been interpreted in terms of hydrophobic interactions between complexed counterion and amphipatic anion.