The present study explored the gamma-rays shielding characteristics of waste soda-lime glass (SLG) containing lanthanum oxide (La2O3) and gadolinium oxide (Gd2O3) by utilizing theoretical and experimental determinations. For this purpose, both La2O3, and Gd2O3 were separately added as 0.005, 0.05, and 0.5 wt% in place of waste SLG. The glass series of SLGL and SLGG were successfully fabricated via conventional melting techniques. Some physical analyses were done while radiation shielding parameters were figured out by using gamma-rays spectroscopy and XCOM computations to the produced glass specimens. One can easily state that the synthesized glasses showed a transparent appearance without any glass defects. Further, the glass density revealed an increasing trend with the insertion of both substances, but the SLGG series enhanced more. According to the experimental measurements, it was figured out that both oxide additions had the ability to increase the linear attenuation coefficient (LAC) values. The LAC was improved from 0.151 to 0.242 cm(-1) for Gd2O3 insertion ration whereas 0.148 to 0.202 cm(-1) for La2O3 series. Moreover, a good agreement between the experimental measurements and theoretical calculations was fulfilled. Based on the measured LAC values, other important parameters including mass attenuation coefficient (MAC), half-value layer (HVL), and mean free path (MFP) were evaluated for the investigated glass series. All in all, the authors concluded that SLGG3 glass can compete with commercial radiation shielding glasses.