A range of reactions have been carried out using 11-bromoundecanoic acid attached to polymer supports in an attempt to prepare the first catenated polymers. In one series of reactions, cyclization of the polymer-supported polyester chains was effected in the presence of sharp fractions of polydimethylsiloxane rings, but no evidence of catenane formation could be found. Instead, a white crystalline product polyester was obtained. Its identity is discussed here. In another series of reactions, polymer-supported linear polyesters were cyclized in the presence of recycled cyclic polyesters. Gel permeation chromatographic analyses showed that substantial quantities of high molar mass material had been formed. This material may prove to be the first catenated polyesters to be prepared.