Y3Al5O12 (YAG) nanoceramics fabricated by low-temperature high-pressure sintering were investigated using Raman and FT-IR techniques. It was found that the Raman scattering intensity decreased significantly with increasing sintering pressure. The spectra showed also broadening of the Raman and IR bands. The XRD and TEM studies showed that during fabrication of nanoceramics the average grain size decreased and a partial amorphization took place. It was concluded that these effects are responsible for the changes in the Raman and FT-IR spectra. (C) 2010 Elsevier B. V. All rights reserved.