Carbon quantum dots (CQDs) are gaining more attention than traditional semiconductor quantum dots due to their intrinsic fluorescence, chemical inertness, biocompatibility, non-toxicity, and simple, inexpensive synthesis. These properties make CQDs suitable for a wide range of applications in biomedical sciences, particularly in bioimaging and biomedicines. CQDs doped with heteroatoms or polymer composites are advantageous for biochemical, biological, and biomedical applications due to their ease of preparation, biocompatibility, and beneficial properties. This review explores the applications of CQDs in bioimaging and biomedicine, highlighting recent advancements and future possibilities to increase interest in their numerous advantages for therapeutic applications. CQDs are synthesized using top-down or bottom-up methods. Top-down methods include arc discharge, laser ablation, and acidic oxidation, while bottom-up methods include combustion, hydrothermal, microwave, pyrolysis, and template techniques. Each method has its advantages and challenges, with top-down methods often yielding high-quality CQDs but being costly and producing hazardous byproducts, while bottom-up methods are more cost-effective but may have poor size control. CQDs have unique properties such as high quantum yield, stable red and near-infrared emission, and the ability to be functionalized with various groups, making them useful in bioimaging, phototherapy, gene therapy, and drug delivery. Their biocompatibility and ability to penetrate cells make them suitable for in vivo imaging. CQDs can be used for imaging various cellular compartments and organelles, providing insights into diseases like Alzheimer's, Parkinson's, and cancer. They also have potential in drug delivery, where they can be functionalized to target specific cells or tissues. CQDs are also used in biomedical applications such as cancer treatment, where they can be combined with chemotherapy drugs to improve targeting and reduce side effects. They can be functionalized with ligands like folic acid to enhance cellular uptake and retention. Additionally, CQDs have potential in photodynamic therapy and as contrast agents in imaging techniques like photoacoustic imaging. The review highlights the various synthesis methods, properties, and applications of CQDs in bioimaging and biomedicine, emphasizing their potential for future research and development in these fields.Carbon quantum dots (CQDs) are gaining more attention than traditional semiconductor quantum dots due to their intrinsic fluorescence, chemical inertness, biocompatibility, non-toxicity, and simple, inexpensive synthesis. These properties make CQDs suitable for a wide range of applications in biomedical sciences, particularly in bioimaging and biomedicines. CQDs doped with heteroatoms or polymer composites are advantageous for biochemical, biological, and biomedical applications due to their ease of preparation, biocompatibility, and beneficial properties. This review explores the applications of CQDs in bioimaging and biomedicine, highlighting recent advancements and future possibilities to increase interest in their numerous advantages for therapeutic applications. CQDs are synthesized using top-down or bottom-up methods. Top-down methods include arc discharge, laser ablation, and acidic oxidation, while bottom-up methods include combustion, hydrothermal, microwave, pyrolysis, and template techniques. Each method has its advantages and challenges, with top-down methods often yielding high-quality CQDs but being costly and producing hazardous byproducts, while bottom-up methods are more cost-effective but may have poor size control. CQDs have unique properties such as high quantum yield, stable red and near-infrared emission, and the ability to be functionalized with various groups, making them useful in bioimaging, phototherapy, gene therapy, and drug delivery. Their biocompatibility and ability to penetrate cells make them suitable for in vivo imaging. CQDs can be used for imaging various cellular compartments and organelles, providing insights into diseases like Alzheimer's, Parkinson's, and cancer. They also have potential in drug delivery, where they can be functionalized to target specific cells or tissues. CQDs are also used in biomedical applications such as cancer treatment, where they can be combined with chemotherapy drugs to improve targeting and reduce side effects. They can be functionalized with ligands like folic acid to enhance cellular uptake and retention. Additionally, CQDs have potential in photodynamic therapy and as contrast agents in imaging techniques like photoacoustic imaging. The review highlights the various synthesis methods, properties, and applications of CQDs in bioimaging and biomedicine, emphasizing their potential for future research and development in these fields.