The extraction and characterization of chitin from four sources of Nigerian origin was investigated. Chemical demineralization and deproteinization was done to obtain the chitin. Proximate analysis, XRD and SEM analysis were conducted on obtained chitins. The investigation revealed that the shrimp had the highest yield of chitin of 8.15%, crab, crayfish and periwinkle had yields of 7.8%, 2.88% and 0.44% respectively. The proximate analysis showed that chitin from shrimp had highest moisture and protein content of 8.70% and 4.16% respectively. Crayfish had the highest ash and fiber content of 7.20% and 6.98% respectively. Crab has the highest lipid content of 1.70%. The SEM analysis showed very uniform structure with a lamellar organization and less dense structure for chitin from shrimp and the surface of chitin from crayfish consists of fibers that form parallel thread networks. XRD analysis showed that chitin from shrimp was more crystalline than others.