Composite films consisting of nickel hydroxide and cationic polyelectrolytes, such as polyethylenimine ( PEI) and poly( diallyldimethylammonium chloride) ( PDDA) were obtained via cathodic electrodeposition. Films up to 3 mum thick were obtained on Pt, graphite and carbon felt substrates. By varying the concentration of the polyelectrolytes in solutions and deposition time, the amount of the deposited material and its composition can be varied. The deposits were studied by thermogravimetric analysis, X- ray diffraction analysis and scanning electron microscopy. The mechanisms of electrochemical intercalation of the cationic polyelectrolytes into nickel hydroxide deposits are discussed.