This paper reports the structural and optical modifications of Y2O3:Eu3+ nanophosphor induced by 150 MeV Ni7+ swift heavy ions (SHI) in the fluence range 1 x 10(11) to 1 x 10(13) ions/cm(2). The XRD, TEM and FTIR studies confirm the loss of crystallinity of the nanophosphors after ion irradiation. Diffuse reflectance spectrum shows a blue shift in the absorption band for SHI induced nanophosphors. An increase in the intensity of photoluminescence peaks without any shift in the peak positions was observed. (C) 2012 Elsevier Ltd. All rights reserved.