Cartilage of chicken keel bone is a by-product obtained from the filleting stage of chicken breast fillets, which cartilage is characterized as a high-value by-product, rich in proteins, with potential for technological, biochemical and biomedical applications. The objective of this study was to perform partial chemical characterization and protein profile of keel cartilage and to study an acid pretreatment for extraction of collagen as a function of organic acid type (acetic, lactic and citric acid) and extraction time (24, 48 and 72 hours). Also, optimization studies of enzymatic acid extraction of chicken keel cartilage collagen were performed, as a function of the percentage of enzyme pepsin (0.1 - 0.55 - 1.0%) and extraction temperature (4, 17 And 30 ° C). The study cartilage presented high protein content (> 90% b.s.), consisting of approximately 35.7% of collagen (b.s.), besides being a source of essential amino acids, which revealed the existence of a predominantly hydrophobic profile. The use of acetic acid for 24 hours proved to be the best pre-treatment, generating the highest yield in collagen (30.12%), and consequently a higher percentage of extraction. In addition, the electrophoretic characterization revealed the existence of an α1 chain, indicating the presence of type II collagen. The optimization study of the method of extraction of cartilage from chicken keel bone showed that the best extraction conditions were obtained with 1% pepsin at 30 ºC to obtain 66.05%. The use of 30 ºC in the enzymatic acid extraction process indicated a probable reduction of extraction process costs. In this way, the research evidenced a new technological option for the utilization of by-products of poultry cutting adding value to this activity.