We introduce a method permitting remote control of the crystallization of thin polymer films, which does not require changes in the film thickness or the interfacial chemistry. The procedure is based on the assembly of hybrid multilayers, where ultrathin films of a crystallizable polymer-poly(ethylene terephthalate), PET,-are embedded in parallel with noncrystalline polymer layers-polystyrene, PS,-into metallic slabs. Variation of the size of the PS film allowed tuning the crystallization rate of PET layers of constant thickness. We demonstrate that this phenomenon is ascribable to an increase in the interfacial dispersive forces that, enhancing physisorption of PET at the polymer/metal interface, causes a shortage of material at the crystal growth front.