The present study was carried out to investigate the toxic effects of waterborne cadmium chloride (CdCl₂.H₂O) on Oreochromis niloticus and the possible protective role of quick lime (CaO) against Cd toxicity. Fish weighing 44.55±2.96 g were exposed to 1 and 2 mg CdCl₂ L^-1 individually and in mixture with quick lime 60 mg CaO L^-1 for 30 days followed by 15 days recovery. Although, the results revealed a slight decrease in final weight (W) and total length (TL) of Oreochromis niloticus exposed to sublethal concentrations of cadmium (1 and 2 mg CdCl₂ L^-1) individually and in mixture with quick lime (60 mg CaO L^-1) for 30 days in comparison with the control groups, a non-significant differences were recorded in fish condition factor (K) of the different studied treatments. However, there was a significant (p<0.05) decrease in the hepato-somatic index (HSI) in Cd-treated fish as compared to the control ones. The accumulation of Cd in muscles, gills and livers of fish were significantly (p<0.01, p<0.001 and p<0.001, respectively) increased with increasing Cd concentration in all Cd-treated groups compared to controls. The accumulated pattern of Cd in these tissues was in the following order: livers>gills>muscles. Moreover, quick lime play a role as a protective agent in eliminating residual Cd from the studied vital organs and improve fish growth indices to levels more or less similar to control groups.