Owing to its physico-chemical characteristics, the biodegradable and biocompatible polymer derived from crustacean shells, Chitosan is one of the preferred candidates for green biomedical applications and also for several industries. Its solubility in acid solutions and ability to form complexes with anionic macromolecules to yield nanoparticles, microparticles and hydrogels, as well as the ability of chitosan based nanocomposites to remain stable at physiological pH recommend this polymer for the development of efficient drug delivery systems. This paper reviews the main utilities of chitosan as a drug delivery component and describes the most recent technologies which utilize this polymer for developing nanostructured systems with antimicrobial effect, offering a perspective of using these findings in new, ecological biomedical applications.