The optimized concentration of oxygen vacant sites along with surface spin alignment in the nanoparticles can lead to the origin of ferromagnetism in them. So in this work, indium-tin-oxide was doped with iron by varying the concentration of Fe. Thus, cubic structured iron doped indium tin oxide nanoparticles were obtained with increasing crystallinity. Even the relative intensity ratio was found to be below 29% suggesting the optimization of amount of oxygen vacancies. Room temperature ferromagnetism was observed in case of Fe: ITO nanoparticles. © 2020 Author(s).