Hybrids of natural polymers with synthetic polymers are of great interest because of their application as biomedical and biodegradable materials. One of the natural polymers that has attracted much recent attention is chitosan, a polysaccharide obtained by alkaline deacetylation of chitin, exhibiting excellent biological properties such as biodegradability in the human body and immunological, antibacterial, and wound-healing activities. Chitosan has also been found to be a good candidate as a support material for gene delivery, cell culture, and tissue engineering. In this review we have presented the current applications of the various types of chitosan derivatives synthesized in the fields of drug delivery, tissue engineering, wound healing, antimicrobials, biotechnology, pharmaceutics, and cosmetics.