This article fuses the world of benzoxazine chemistry with the field of polyelectrolyte chemistry and introduces a new approach toward water-soluble polybenzoxazines. The synthesis of a novel class of polybenzoxazine-based polyelectrolytes carrying cationic charges in the side chain and/or the backbone is described. Tertiary nitrogen atoms of the backbone or side chain have been methylated in a polymer analogous reaction leading to cationic polybenzoxazines with structure dependent, adjustable solubility in various solvents including water providing unique hydrogen-bonding capabilities. The polymers have been investigated by (13)C NMR, SEC, TGA, and DSC.