Oil spills on the sea surface cause irreparable damage to marine habitats and ecosystems, mainly caused by oil spills from tankers, offshore platforms, oil drilling platforms and oil wells. The use of adsorbents to absorb and recover oil spills is one of the most advantageous strategies for oil spill treatment because it is economical, has a high recovery rate, and does not cause secondary pollution of the ecosystem. Chitosan is the second most abundant biopolysaccharide in nature and is commonly extracted from crab and lobster shells. It is a biocompatible, biodegradable, non-toxic and renewable substance. It also has reactive amino and hydroxyl groups that can be easily modified to be hydrophobic for oil adsorption. Adsorbents made from chitosan have recently attracted great interest because they are cheap, abundant, biodegradable and ecological. This chapter will discuss some important chitosan-based materials which have been used for oil spill treatment and found to be very efficient.