Silver nanoparticles (AgNPs) have been used as a promising alternative to antibiotics in poultry feed. In this study, silver-doped silica nanoparticles (SiO @AgNPs) were prepared in powder form, using starch, via the chemical reduction method and sol-gel technique followed by full characterization. SiO @AgNPs were added to the poultry diet at three doses (2, 4, and 8 mg/kg diet). The safety of the oral dietary supplementation was estimated through the evaluation of the growth performance and hematological, biochemical, and oxidative parameters of birds. Moreover, the immunohistochemical examination of all body organs was also performed. Results of this study showed that SiO @AgNPs have no negative effects on the growth performance and hematological, biochemical, and oxidative parameters of birds. Moreover, the immunohistochemical examination revealed the minimum inflammatory reactions and lymphoid depletion under a dose level of 8 mg/kg. In conclusion, SiO @AgNPs could be considered as a promising and safe nano-growth promoter in broilers when added to poultry diet under a dose level of 4 mg/kg diet.