The macromolecular complexes Chitosan•(PtCl 2 ) n and PSP-co-4-PVP•(PtCl 2 ) n , were prepared from the respective polymer and PtCl 2 in metal:polymer molar ratios 1:1 and 1:5. Pyrolisis of the macromolecular complexes Chitosan•(PtCl 2 ) n and PSP-co-4-PVP•(PtCl 2 ) n at 800 °C under air affords cubic nanostructured Pt in the pure phase. The morphology of the pyrolityc products depends on the molar metal:polymer ratio; i.e. a "cotton" 3D shape for the 1:1 ratio and a "foamy" 3D shape for the 1:5 ratio. On the other hand, the particle size depends on the polymer nature, obtaining Pt nanoparticles as small as 6 nm for the chitosan precursors in both molar ratio.