The use of byproducts for obtaining biologically valuable products has been attracting interest from industries and consumers. The objective of this study was to optimize the levels of acetic acid, pepsin, and hydrolysis time of collagen extraction in chicken feet and evaluate the formation of peptides in each condition. It conducted 2^3 factorial design with three replications at the center point, totaling 11 experiments. The variables studied were: acetic acid (0.3 to 0.7 mol/L), pepsin (0.1 to 0.2%) and hydrolysis time (12 to 36 hours). The response variables analyzed were the collagen content (Y1) and the sum of peak areas of the peptides (Y2) obtained in each treatment. All trials were subjected to analysis of amino acid profile, hydrophobicity of peptides, electrophoresis (SDS-PAGE) and functional properties such as water solubility at 70 ºC and water holding capacity at 60ºC. The variable Y1 had a significant influence of pepsin and hydrolysis time, the highest content occured with 0.2% of pepsin and 12 hours of hydrolysis time, while for Y2 the variable hydrolysis time was the significant factor. In 36 hours there was further fragmentation of molecules into peptides. In the central point, the water solubility was greater in the collagen isolated. In electrophoresis, there was predominance of type I collagen and the view of fragments in the collagen chains with 36 hours of hydrolysis. The amino acid profile of the collagen isolates showed that all had high levels of glycine, proline and hydroxyproline and that treatment with long hydrolysis showed the highest levels of neutral nonpolar and polar amino acids. Therefore, a larger pepsin content with the shortest time (12 h) produces isolated with high collagen content, while higher hydrolysis times (36 h) results in more peptides content.