Polymer-supported organotin chlorides have been synthesized by suspension copolymerization of organotin-functionalized styrenic monomers using a precipitating porogen. Their activities as reducing catalysts have been evaluated in the reduction of bromoadamantane by sodium borohydride. The influence of the length of the spacer arm between the tin atom and the polymer backbone on the activity and the tin leaching of the supported catalyst have been studied. The nature of the alkyl groups (butyl or phenyl) attached on the tin atom plays an important role on the stability toward successive reuse of the supported catalyst.