Tin oxide (SnO 2) nanoparticles were synthesised using various surfactants of different charges (n-cetyl trimethyl ammonium bromide, sodium dodecyl sulphate and TRITON X-100) by the co-precipitation method. The synthesised nanomaterials were characterised using different techniques to study their structural, surface morphological, optical and antibacterial activities. X-ray diffraction patterns revealed the formation of a tetragonal rutile structure in pure and surfactants-aided SnO 2 nanoparticles and the results show good agreement with JCPDS data [41-1445]. The crystallite size of SnO 2 nanoparticles was found to decrease with the addition of surfactants. Scanning electron microscopy images exhibit spherical shape morphology with an average diameter of 30-75 nm for pure and surfactants-aided SnO 2 nanoparticles. The band gap energy of the prepared materials was estimated from the UV-visible absorption spectra and a considerable increase in band gap energy was observed in surfactants-aided SnO 2 nanoparticles (3.487, 3.57, 3.50 and 3.3 eV). The antibacterial activities of the synthesised nanoparticles were studied against Escherichia coli and Staphylococcus aureus bacteria.