This chapter will provide an overview of different nanomaterials, which are being used for nondestructive imaging of living entities such as cells and tissues. The chapter begins with the basics of fluorescence imaging followed by a discussion on the advantages of fluorescent nanomaterials as compared to commonly used molecular fluorophores and imaging probes. Specific features and applications of nanomaterials frequently exploited in bioimaging are summarized. These include fluorescent silicon-based nanomaterials, hydrogels, polymer dots, magnetic nanoparticles, fluorescent quantum dots, carbon dots and other carbon-based nanomaterials, noble metal nanoparticles, micelles, dendrimers, lipid nanoparticles, and so on. Specific examples on their applications in bioimaging including multimodal imaging and targeted imaging are illustrated.