A novel set of cationic polyelectrolytes has been prepared. The polyelectrolytes have a high cationicity with each segment carrying one positively charged quaternary ammonium group. The polyelectrolytes also contain grafted oligo(ethylene oxide) (EO) chains. The grafted EO chains are, according to NMR measurements, six units long. The graft density of EO chains has been varied and polymers having approximately 100%, 20% and 10% of the segments with a grafted EO chain have been prepared. The obtained products were characterized using 1H and 13C NMR spectroscopy. Aqueous solutions of the cationic polymers were characterized by dynamic light-scattering (DLS) measurements. It was found to be important to include a radical inhibitor to prevent crosslinking reactions during isolation and purification. In general the DLS measurements showed a bimodal size distribution. The majority of the polymers (about 75 wt%) were found to have a hydrodynamic radius of 6-8 nm, with the remaining polymers being dominated by a fraction with a hydrodynamic radius in the range 120-140 nm.