The interactions between an anionic dye, Acid Green 25 AG and the two cationic surfactants tetradecyltrimethylammonium bromide TTAB, and hexadecyltrimethylammonium bromide CTAB in aqueous solutions far below the CMC are studied using the conductometric method at different temperature. The equilibrium constants and other thermodynamic functions for the process of dye-surfactant ion pair formatio...