Thermodynamic cat attacks! Iodide-catalyzed reversible nucleophilic attacks have been exploited to access side-chain polycatenanes under thermodynamic control. Multiple catenations occurring all along the polymer chain are entirely driven to completion by the intra- and intermolecular side-chain - stacking interactions of contiguous catenanes. (Figure Presented) 2010 Wiley-VCH Verlag GmbH & Co. KGaA,.