Strong segregation theory of microphase separation in dilute solutions of associating polyelectrolytes is developed. The driving force of the separation is shown to be a competition between a short-range attraction of associating groups and long-range repulsion of charged groups. We predict that with the increase of polymer concentration single chains first aggregate into spherical clusters of optimum size which can be disordered in space or arranged with the symmetry of the bcc lattice. Further increase of polymer concentration can result in the formation of hexagonal and lamellar structures which precede the physical gelation. The hexagonal and lamellar structures are stable at very small fractions of charged groups on the chains. (C) 2003 American Institute of Physics.