Solubility of water and association of selected surfactants in gasoline modified with hydrophilic modifiers was studied. The solubility of water can also be modified by the presence of amphiphilic substances which, also when present in negligible amounts, can promote the association phenomena with the formation of reversed micelles. The cores of such micelles containing hydrophilic groups located inside the micelle can contain water pools, enhancing in this way the solubility of water and improving some properties for which an aqueous environment is needed. The aim of this work was to study the effect of some hydrophilic additives (alcohols and t-butylmethyl ether) and some selected surfactants (sodium bis-(2-ethylhexyl) sulfosuccinate, calcium dodecylbenzenesulfonate and branched alkylamines) upon the solubility of water in modified gasoline, interfacial tension isotherms at modified/water interfaces. (C) 2007 Elsevier Ltd. All rights reserved.