The interaction of phenolic compounds, phenol (PhOH); 2-chlorophenol (2-Cl-PhOH); 2,5-dichlorophenol (2,5-DCPhOH); 2,6-dimethylphenol (2,6-DMPhOH); and 4-bromo-2,6-dimethylphenol (4-Br-2,6-DMPhOH), in their anionic forms with cetyltrimethylammonium chloride (CTAC) micelles was studied. The concentration of phenoxide ions in the micellar pseudophase was measured from the observed absorbance changes upon the addition of detergent to an alkaline aqueous solution. The luminescence quenching of tris(2,2’bipyridine)ruthenium(II) dichloride was used to measure the concentration of phenoxide ions in the intramicellar aqueous pseudophase for 2,6-DMPhOH and 4-Br-2,6-DMPhOH. To apply this method, two different series of quenching experiments were carried out in which the quencher concentration and the CTAC concentration were either varied or fixed. The results can be interpreted in terms of binding to a single class of independent binding sites. The site-binding constants (K(b)), their respective site numbers per micellized detergent (p), and the critical micelle concentration of the detergent in the presence of the substrates were obtained.