The surface of a polypropylene (PP) film was modified using acetone and acetone/oxygen. Significant improvement in surface energy was observed due to plasma treatment. The chemical nature and stability of the surface modification was studied by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The relative change in intensity was calculated for C-H stretch vibrations of a modified PP film to understand the reactive site for surface modification. Studies were carried out to mask the reactive site of PP by pretreatment in nitrogen plasma followed by treatment in acetone/oxygen. The peel strength and effect of aging were studied on acetone and acetone/oxygen plasma modified films.