Nanocrystalline erbium doped yttrium oxide (Y2O3:Er 3+ ) was synthesized by the sol-gel technique using citric acid as complexing agent. The synthesized samples were characterized by X-ray diffraction (XRD), Field emission scanning electron microscope (FE-SEM) techniques for phase-purity and microstructure. Er 3+ doped Y2O3 crystallizes in cubic phase with an average crystallite size of 24.3 nm. The pellets of Y2O3:Er 3+ were irradiated with 100 MeV swift Si 8+ ions with fluence in the range of 3×10 11 - 3×10 13 ions cm -2 . Three well resolved thermoluminescence (TL) glows with peaks at ~422, 525 and 620 K were observed in Er 3+ doped Y2O3 samples. It was observed that the TL intensity was found to increases with increasing Er 3+ concentration up to 0.4 mol% in Y2O3 and thereafter it decreases with further increase of Er 3+ concentration. Also, the intensity of low temperature TL glow peak (~422 K) increases with increasing ion fluence up to 1×10 12 ions cm -2 and decreases with further increase of ion fluences. The TL trap parameters were calculated by glow curve shape method and the deconvoluted glows were exhibit of second order kinetics.