We have studied the interpolyelectrolyte complexation in chloroform between polystyrene-block-poly(cetyltrimethylammonium acrylate), (PA(-) CTA(+)), and poly(2-(methacryloyloxy)ethyldimethylethyl-ammonium dodecyl sulfate) (quaternized poly(2-(dimethylamino)ethyl methacrylate) complexed with sodium dodecyl sulfate), (PDMAEMAQ(+) DS(-)). Turbidimetry, dynamic/static light scattering, and transmission electron microscopy show the formation of large aggregated interpolyelectrolyte complex species, which are colloidally stable in chloroform or even chloroform-soluble if the certain conditions are met. We suggest such co-assemblies to be micellar species with a core assembled from electrostatically coupled fragments of the polymeric components. The corona is built up either from a mixture of polystyrene blocks and excessive fragments of (PDMAEMAQ(+) DS(-)) chains or from a mixture of polystyrene blocks and excessive fragments of (PA(-) CTA(+)) blocks, depending on which polymeric component was taken in excess for the interpolyelectrolyte complexation. However, their real structures may deviate from such idealized consideration because of the non-equilibrium character of interpolyelectrolyte complexation in organic media of low polarity. (C) 2011 Elsevier Ltd. All rights reserved.