The field of nanotechnology is one of the most emerging scientific areas of interest. However, little emphasis has been put on the characterization and safety evaluation of nanoparticles. The present article covers some of the important aspects of characterization and safety evaluation parameters of nanomaterials. Characterization of nanomaterials is an important aspect of nanotechnology as the particle size/hydrodynamic diameter, surface charge/zeta potential and morphology of nanomaterials highly impact the transport and interaction of the nanomaterials with the target cell or receptor. Different characterization techniques used are dynamic light scattering, zeta potential, encapsulation efficiency, X-ray diffraction study, transmission electron microscopy, scanning electron microscopy, atomic force microscopy, and spectroscopic studies such as UV-visible spectroscopy and Fourier transform infrared spectroscopy. Different safety assessment parameters such as the Proliferation assay, Apoptosis assay, Necrosis assay, Oxidative stress assay, DNA damage assay, and Hemolysis assay can be carried out in order to evaluate the safety of the synthesized nanoparticles.