In recent decades, the invention of nanomaterials and their booming progression has been extended to bioremediation applications as well. As with nanotechnology and its advancement, there is alwaysahigh demand for its analytical details to custom-design nanomaterials. Various nanomaterials including nanoparticles and nanocomposites were positively reported as bioremediators, which possess unique physiochemical properties, viz., dimension, shape, configuration, purity, surface properties, etc. All these parameters are prominently important to custom-tailor nanomaterials for bioremediation applications. Nanotechnology ultimately aims to develop nanomaterials with shapes and sizes of high uniformity. Hence, isamandatory requirement to standardize, optimize, and advance nanomaterial's characterization techniques, which enables researchers to successfully incorporate nanotechnology applications over bioremediation resolutions. This chapter vastly discusses various nanomaterial's characterization techniques (SEM-EDX, TEM, AFM, FTIR spectroscopy, Raman spectroscopy, XRD), which are employed as bioremediators. © 2022 Elsevier Inc. All rights reserved.