A simple and effective strategy is presented to integrate individual platinum nanoparticles (NPs) into macroscopic thin films based on the reduction of organoplatinum(II) complexes [PtCl2(cod)] 1a, [PtI2(cod)] 1b (cod = 1,5-cyclooctadiene) and cis-[Pt(p-MeC6H4)2(SMe2)2] 2, at the toluene-water interface in the absence of stabilizer. Structure and morphology of the platinum NPs were characterized with X-ray diffraction (XRD), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) techniques. Finally, platinum thin films were deposited on glassy carbon electrode and their electro-oxidation was investigated in the methanol oxidation reaction. Pt NPs thin films showed highly improved electrocatalytical activity toward methanol oxidation as compared with commercial platinum catalysts. The present method provides a facile and low-cost strategy toward the synthesis of different electrocatalysts of noble metals for application in fuel cells.