Background: Wastewater considered as a lost economical value, due to it contains a huge content of bacteria that could biosynthesis of a valuable materials from hazardous material. Heavy metals that found in wastewater considered as row material for bacteria to biosynthesis nanoparticles as lead sulfide (PbS) which used as semiconductor. Aim: The present study aims to biosynthesis and characterization of lead sulfide nanoparticles using bacteria isolated from wastewater Materials & Methods: Sampling different samples from three places at different stages in the wastewater plant. Samples were collected from influent (raw sewage), from the outlet of the 2ry sedimentation tank (after biological treatment) and from the outlet after chlorination (effluent). Determine of physico-chemical characteristics of the wastewater samples. Isolate some of bacteria present in these different stages of treatment in the plant. Study the capabilities of the isolated strains for lead resistance. Determine the minimum inhibitory concentration of selected bacterial strains that are resist to lead concentration. Biosynthesize lead nanoparticles using the selected bacterial isolate. Characterize the lead nanoparticle produced by selected bacterial isolate. Results: The biosynthesis of lead nanoparticles by Serratia plymuthica, which isolated from Zenine wastewater treatment plant, Giza, Egypt. Serratia plymuthica had ability to resist lead till 80mg/l and had ability to biosynthesize lead nanoparticle. UV-Vis spectroscopy results for pellets of Serratia plymuthica inoculated in Tryptic soy bean broth (TSB) containing 80 mg/l of Pb(NO3)2show formation of peak at ~ 330 nm, which was a specific peak for lead nanoparticles. TEM image for pellets of Serratia plymuthica inoculated in TSB containing 80 mg/l of Pb(NO3)2show formation of Pb NPs intracellular and extracellular and cells aggregation. Dynamic light scattering (DLS) results show ability of Serratia plymuthica to biosynthesis PbNPs with mean diameter 92.93 nm. X- ray diffraction (XRD) results show ability of Serratia plymuthica to biosynthesis PbS which had semiconducting properties and used in solar cells manufacturing. Conclusions: The results approved the biosynthesis of PbS nanoparticles by Serratia plymuthica which isolated from wastewater.