The kinetic parameters of the transesterification processes of carboxylic acid esters under the action of alkylphenolates in aqueous micellar solutions of cetyltrimethylammonium bromide (CTAB) are found. The observed catalytic effect is due to a complex mechanism of the solvent effect, which includes a shift of acid-base equilibria in the nucleophile and the formation of mixed CTAB/alkylphenol micelles. The dynamic structure of these aggregates (size, diffusion mobility, and molecular packing density in a surface layer) has been characterized by spin-probe EPR spectroscopy and high-resolution pulsed-field gradient 1H NMR spectroscopy.