This review article provides an overview of various nanoparticles (NPs) commonly used in fluorescent bioimaging, focusing on their applications in imaging cells and tissues. It discusses the advantages of fluorescent NPs over molecular fluorophores, labels, and probes, highlighting their improved brightness, inertness, and ability to provide more even distribution. The article covers a wide range of nanomaterials, including fluorescently doped silicas and sol-gels, hydrophilic and hydrophobic polymers, semiconducting polymer dots, quantum dots, carbon dots, upconversion NPs, noble metal NPs, and dendrimers. It also discusses methods for surface modification of NPs and their use in various imaging applications, such as plain fluorescence imaging, targeted imaging, imaging of chemical species, and temperature imaging. The article also covers multimodal imaging, imaging combined with drug and gene delivery, and imaging combined with therapy or diagnosis. The review includes 273 references in the main text and 157 in the electronic supplementary information (ESI). The article emphasizes the importance of selecting the appropriate material for a specific imaging application, considering factors such as biocompatibility, toxicity, and the ability to provide high-resolution imaging. It also discusses the potential cytotoxicity of NPs and the need for further research in this area. The review concludes with a discussion of the future directions in the field of fluorescent bioimaging using nanoparticles.This review article provides an overview of various nanoparticles (NPs) commonly used in fluorescent bioimaging, focusing on their applications in imaging cells and tissues. It discusses the advantages of fluorescent NPs over molecular fluorophores, labels, and probes, highlighting their improved brightness, inertness, and ability to provide more even distribution. The article covers a wide range of nanomaterials, including fluorescently doped silicas and sol-gels, hydrophilic and hydrophobic polymers, semiconducting polymer dots, quantum dots, carbon dots, upconversion NPs, noble metal NPs, and dendrimers. It also discusses methods for surface modification of NPs and their use in various imaging applications, such as plain fluorescence imaging, targeted imaging, imaging of chemical species, and temperature imaging. The article also covers multimodal imaging, imaging combined with drug and gene delivery, and imaging combined with therapy or diagnosis. The review includes 273 references in the main text and 157 in the electronic supplementary information (ESI). The article emphasizes the importance of selecting the appropriate material for a specific imaging application, considering factors such as biocompatibility, toxicity, and the ability to provide high-resolution imaging. It also discusses the potential cytotoxicity of NPs and the need for further research in this area. The review concludes with a discussion of the future directions in the field of fluorescent bioimaging using nanoparticles.