Silver (Ag) and palladium (Pd) nanoparticles were synthesized via a green synthesis route, which was mediated with the extract of Daucus carota leaves. The morphological, crystalline and structural nature of synthesized nanoparticles was characterized by UV-Vis spectrophotometer, TEM, XRD and FT-IR analyses. High antibacterial activities of the prepared Ag and Pd nanoparticles were observed towards different water-borne pathogens of Klebsiella pneumonia, Vibrio cholera and Escherichia coli. The catalytic efficiency of the prepared nanoparticles for the removal of rhodamine 6G (Rh-6G) dye was also evaluated. Nearly 98% of the Rh-6G dye was decolorized by the synthesized Pd nanoparticles within two minutes, and the synthesized Ag nanoparticles took 30 min for 89.4% decolorization. This work provided greener nanocatalysts for pollutants treatment and demonstrated the power of green biosynthesis for metallic nanoparticles.