Undoped cadmium oxide along with samarium doped CdO are synthesized by simple soft precipitation method. Resulting precursor was calcined at 400 °C for 2 h. As a result of heating, a pure material was produced. The obtained compound possesses a cubic crystalline structure at nanoscale. Also, FESEM image showed that the resulting material is composed of nanoparticles and its size decreases with increase of Sm doping relative with the particle size calculated from XRD. The photoluminescence shows the emission of violet and blue colour peaks and the peak at 468 nm which is responsible for a better antibacterial activity. The synthesized nanopowders are subjected to two different gram positive (Staphylococcusaureus and Enterococcusfaecalis) and two different gram negative (Escherichiacoli and Klebsiellapneumoniae) bacterial strains respectively. It is noted that there are high activity of the Sm doped CdO towards gram negative bacteria.