The preparation of platinum-poly{acrylamide-co-[3-(acryloylamino)-propyltrimethylammoniumchloride]} catalysts is described. The influence of copolymer proportion and average molecular weight on the activity in the gas phase hydrogenation of cyclohexene has been analyzed. Copolymers of the composition 90% acrylamide/10% quaternary compound and molecular weights around 919,000 g/mol proved to have the highest efficiency Cyclohexane and benzene were found as reaction products. The nature of the active species was investigated with FTIR measurements of adsorbed carbon monoxide. Platinum in the zero-valent state, electronically influenced by the carrier, was identified as the agent responsible for the hydrogenation properties of the catalyst. Selectivities are given for some additional test reactions.