Nano metaloxides have been considered as an important reactive adsorbent in waste water treatment due to their unique physicochemical properties. This work reports the preparation of eco-friendly nanoadsorbent ZnO and Mn doped ZnO using Eclipta erecta plant extract. Eclipta erecta effectively reduced the precursor of metal oxide nanoparticles and acts as a surfactant to minimize agglomeration of nanoparticles during synthesis. The prepared samples were characterized by XRD, FTIR, UV-Vis, fluorescence spectra, FTIR, and FESEM analytical techniques. XRD results revealed the hexagonal phase of ZnO and Mn doped ZnO nanoparticles. FESEM analysis revealed that ZnO and Mn doped ZnO are roughly spherical and particles size were in ranging from 80 – 150nm. Heavy metal adsorption efficiency of Mn doped ZnO nanoparticles were analyzed using ICP-OES and compared with undoped ZnO nanoparticles. Results indicate that Mn doped ZnO nanoparticles exhibited an maximum adsorption of heavy metal ions Hg(89.01%), Cr(91.21%), Cd(96.02%), Ni(97.03%) and Pb(97.05%). Experimental results indicate that prepared Mn doped ZnO nanoparticles could be an effective nanoadsorbent for heavy metal removal from waste water.