Wastewater from processes carried out in automotive repair shops contains oils, detergents, greases and other chemical products that are mostly discharged directly into the sewage system without prior treatment. Thus, this research determined the efficiency of the sponge from crab chitosan for the reduction of oils and greases from the wastewater of an automotive repair shop. The extraction of chitosan from crab exoskeletons occurred by demineralization, deproteinization and chemical deacetylation. The sponges were elaborated with chitosan concentrations of 5, 10 and 15 mg/mL, obtaining oil and grease removals of 75.26% with the highest concentration used and at pH 3.8. In addition, parameters such as BOD5 and COD had reduction values of 63.15 and 59.51%, respectively. Finally, it is concluded that the chitosan sponge is a viable option for future wastewater treatment research.