Research on nanostructures continues to evolve with the growth of nanotechnology for diagnostic and therapeutic clinical applications. It is imperative to determine the safety and efficacy of a nanobiomaterial for any specified application. Due to the diverse properties of nanostructures and many unrecognized factors in biological environments, selection of appropriate experiments for determination of injurious effects on biological systems must be precisely performed and interpreted. Although various techniques have been proposed for toxicity evaluation of nanomaterials, to date no single assessment is sufficient. Toxicity observation is initiated by the observation of the cell's response to a nanomaterial which has been preceded by studies in animal models for genotoxicity, immunotoxicity, carcinogenicity or hemolysis. In this text, common methods for evaluation of nanomaterial toxicity are introduced and briefly described.