This work has been done to produce a silver nanoparticles by using a type of bacteria which considered a pathogenic bacteria , this bacteria was isolated from clinical samples in Iraq (vagina), the isolates which previously identified as Proteus vulgaris by using PCR technique. Then the cytotoxic effect of the bacteria against MCF-7 cell line was studied. The cytotoxic effect of Proteus vulgaris against (MCF-7) cell line using 400 μg/ml reached 58.67 % from a cytotoxicity standpoint, this level of growth inhibition is tolerable. In vitro cytotoxic activity of Ag NPs against the MCF-7 cell line was achieved using 400g/ml ,growth suppression was 64.59 percent when nanoparticles were coupled with growth of bacteria (Proteus vulgaris) at the same concentration of AgNPs, the growth inhibition of MCF-7 cells increased to 73.55 percent.