© 2021 Wiley-VHCA AG, Zurich, Switzerland.Protein-inorganic hybrid nanoflowers have tremendous potential in bionanotechnology due to their simple method of preparation, high stability and superior properties. Considering these features, the present study was designed to investigate the artificial blood substitution potentials of hemoglobin-inorganic hybrid nanoflowers. In this context, hemoglobin-inorganic hybrid nanoflowers (Cu-NF, Co-NF and Zn-NF) were synthesized using with different metal ions (copper, cobalt and zinc), then their oxygen carrying capacity, the hemolytic studies, in vitro oxidant/antioxidant capacity levels and oxidative stress index were reported for the first time. The present findings have revealed that Zn-NF had significant oxygen content and artificial oxygen carriers (AOC), as well as a significantly low percent hemolysis rate and a safe standard value. Also, hemolysis rate decreased along with the increases in hemoglobin content coupled with increments in nanoflower concentrations. The percentage hemolysis rate was lower than all nanoflowers at low free hemoglobin concentration, but hemolysis rates also increased with increments in concentration. The results showed that in general, Zn-NF stands out with its high total antioxidant capacity and low total oxidant capacity and oxidative stress index. The obtained results showed that Cu-NF and Co-NF, especially Zn-NF might be considered as a potential superior artificial oxygen carrier. Therefore, this nanoflower system might be act as an efficient material as a blood substitute in the near future.