Thermoluminescence (TL) studies on PbO–Al₂O₃–SiO₂:Nd³⁺ glasses mixed with varying concentrations of Al₂O₃ exposed to γ-rays of dose in the range 0–5.0 kGy were carried out. The TL emission exhibited a dosimetric peak at about 185 °C. The TL output under the glow peak increased with increasing Al₂O₃ and also with the γ-ray dose. The mechanisms responsible for TL emission and enhancement of TL output with increase in the concentration of Al₂O₃ were quantitatively discussed in terms of induced structural defects in the vicinity of Nd³⁺ ions due to interaction of γ-rays with the glass network in the scenario of varying concentration of Al₂O₃. The dose response of these glass samples exhibited linear behavior in the medium dose range viz., 1.0–3.0 kGy. Finally, it is concluded that the glass containing the highest concentration of Al₂O₃ exhibits high TL output and such glasses are useful for dosimetry in the range 1.0–3.0 kGy and hence these glasses may be useful for dosimetry in such high range of doses required for commercial radiation processing of perishable food commodities to extend their shelf-lives.