In the present study, indium-tin-oxide (ITO) nanoparticles were synthesized using solid-state reaction and studied for their structural, vibrational and magnetic properties. The ITO nanoparticles were prepared under reduced pressure, which can increase the oxygen vacancies in the samples. The X-ray diffraction studies confirmed singe-phase cubic bixbyite structure of ITO with average crystallite size of 47 nm. The lattice vibrational studies (FTIR and Raman spectroscopy) at room temperature indicated that Sn ions were occupied in In2O3 lattice and gives corresponding active vibrational modes in the respective spectra. The magnetic studies at room temperature reveal the ferromagnetic nature of ITO and the strength of magnetization is superior to those of In2O3 and SnO2. However, the magnetic studies at 100 K revealed reduced ferromagnetism, which could be attributed to reduced itinerary electrons at low temperature. Blue and blue-green emissions were found from the ITO nanoparticles, which could be due to vacancies or surface defects present in the system. © 2017 Indian Academy of Sciences.