In the last few decades, chitosan-based nanostructured materials have attracted significant attention and have been applied in different biomedical fields. Chitosan-based nanogels with appealing physical and biological characteristics have been developed for various biomedical applications due to their excellent properties related to biocompatibility, biodegradability, antibacterial activity, low immunogenicity, large surface area, and stimuli responsiveness. Numerous approaches, such as physical gelation, self-assembly, polymerization, ionic gelation and microemulsion, have been employed to fabricate chitosan-based nanogels with multiple functionalities. These nanogels are promising as effective vehicles for drug delivery, cell culture, bioimaging and therapy. This paper reviews recent progress in the preparation and application of engineered chitosan-based nanogels in biomedical fields.