Aromatic polyelectrolytes based on sulfonated poly(benzobisthiazo1es) (PBTs) have been synthesized by a polycondensation reaction of sulfo-containing aromatic dicarboxylic acids with 2,5-diamino-1,4-benzenedithiol dihydrochloride (DABDT) in freshly prepared polyphosphoric acid (PPA). Several sulfonated PBTs, poly [ (benzo[ 1,2-d : 4,5-d]bisthiazole-2,6diyl)-2-sulfo-1,4-phenylene] sodium salt (p-sulfo PBT), poly [ (benzo[l,2-d : 4,5d']bisthiazole-2,6-diyl)-5-sulfo-1,3-phenylene] sodium salt (rn-sulfo PBT), their copolymers, and poly[(benzo[ 1,2-d : 4,5-d]bisthiazole-2,6-diyl)-4,6-disulfo-l,3-phenylene] potassium salt (rn-disulfo PBT), have been targeted and the polymers obtained characterized by 13C-NMR, FT-IR, elemental analysis, thermal analysis, and solution viscosity measurements. Structural analyses confirm the structures of p-sulfo P B T and rn-disulfo PBT, but suggest that the sulfonate is cleaved from the chain during synthesis of rn-sulfo PBT. rn-Disulfo P B T dissolves in water as well as strong acids, while p-sulfo P B T dissolves well in strong acids, certain solvent mixtures containing strong acids, and hot DMSO. TGA indicates that these sulfonated PBTs are thermally stable to over 500Β°C. Free-standing films of p-sulfo PBT, cast from dilute neutral DMSO solutions, are transparent, tough, and orange in color. Films cast from basic DMSO are also free standing, while being opaque and yellow-green. p-Sulfo P B T was incorporated as the dopant ion in polypyrrole, producing conductive films with conductivities as high as 3 S/cm and electrical anisotropies as high as 1 0 . 0