Adsolubilization of naphthalene, 1-naphthol, and 2-naphthol is demonstrated by atomic force microscopy imaging to cause changes in the adsorbed layer structure of quaternary ammonium surfactants at the mica/aqueous solution interface. Surface compositions for both surfactants and additives, derived from HPLC measurements of solution depletion, support the existence of shape transitions and of nonideal effects in the adsolubilization of these solutes.