Untanned Pickled skin waste is a solid byproduct obtained before the tanning process and is characterized by its high protein and acid content. Despite its richness in protein compounds, this particular waste stream within the tannery industry remains underutilized. Animal glue, derived from the extended boiling of animal connective tissue waste obtained from the tannery industry, serves as a specific type of adhesive. The objective of this study was to extract animal glue from untanned pickled leather waste and enhance its physico-chemical and mechanical properties by incorporating a renewable carboxyl methylcellulose (CMC) additive. Raw materials obtained from the Bahir Dar Tannery were subjected to washing with tap water and pretreatment, involving soaking in water and diluted sulfuric acid to facilitate the partial hydrolysis of collagen peptide. The extraction process was carried out in a water bath, with a soaking concentration ranging between 0% and 1%, a boiling temperature between 60 OC and 80 OC, and a boiling time of 2 to 4 hours. The resulting solution was filtered, and the collagenous material retained on the filter was subsequently dried. After the drying process, the glue was cooled and subjected to characterization. The optimal conditions for extraction were found to be a soaking reagent concentration of 1%, a temperature of 70 °C, and a time of 3 hours, yielding the best results and quality indicators. These indicators included a shear strength of 81.64 MPa, a viscosity of 81 cp, a moisture content of 15.19%, an ash content of 2.08%, a pH of 5.7, and a yield of 49.90 g of glue per 100 g of pickled skin. Furthermore, when the CMC additive (0.4%) was incorporated, improvements were obtained in quality parameters such as viscosity, shear strength, and moisture content, resulting in values of 88.1 cp, 97 MPa, and 15.23%, respectively. This enhancement further improved the durability of the extracted glue. Additionally, the results indicated that both the extracted glue and the enhanced glue exhibited quality parameters comparable to those of commercial glue, which are standard values for shear strength (12 to 13 MPa), viscosity (80 to 90 cp), moisture content (8 to 16%), and ash content (2 to 4.5%). Key words: Pickled leather waste, Improved animal glue, sustainability