In order to investigate the possibility of urea peroxide formation in ɤ- irradiated urea aqueous solutions, we conducted energy-dispersive x-ray (EDS), mass, 1H NMR, and Raman spectral studies on the solid residues (SR) that remains after water evaporation of these solutions. Spectroscopic data of SR for both irradiated and unirradiated samples were analyzed and compared. EDS data show an increase of oxygen content in SR of urea aqueous solutions upon radiolysis. Comparison of mass spectrum of RS of irradiated sample and that of urea shows a significant increase in m/z 16 peak intensity of O+ as well as m/z 61of M+1in the former. The NMR spectrum of SR of an irradiated sample shows a signal down field shift of urea protons, as well as the appearance of new signals, which were assigned to H2O2. The Raman spectral study of both RS and solutions evinces differences in all band positions and intensities for irradiated samples. As a consequence of this study, it seems that the possibility of urea peroxide formation in ɤ- irradiated aqueous urea solution cannot be rolled out.