Nanocrystalline platinum thin films were deposited on quartz and CaF2 substrates using platinum(II)acetylacetonate as a precursor. The depositions were carried out at 420 degreesC in N-2 + O-2, N-2 + O-2 + H2O and N-2 + H-2 atmospheres in order to examine the effect of synthesis conditions on the chemico-physical properties of the layers. Their microstructure, chemical composition and morphology were analyzed by X-ray diffraction, X-ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS) and atomic force microscopy. The obtained results revealed the formation of metallic platinum thin films with no preferential orientation. The presence of C and O contamination, as indicated by XPS and SIMS analyses, is discussed in terms of the precursor decomposition pathway.