The increasing global demand for denim jeans necessitates sustainable practices in both production and disposal. This study investigates the mechanical properties of recycled cotton denim fabric, focusing on tensile strength, tear strength, and fabric density (GSM), in accordance with international testing standards. Results show a decrease in tensile strength but an increase in tear strength for recycled cotton denim. Specifically, there is a strong positive correlation between the tearing strength of the weft yarns in waste and recycled denim (r = 0.797, p < 0.001). Additionally, the recycled fabric has a higher GSM, indicating improved material density. These findings suggest that recycled cotton denim could be used in various durable products, such as handbags and shoes, promoting sustainability within the textile industry. Limitations include the reduced fiber length after recycling, which necessitated blending with raw cotton to achieve optimal quality. Despite equipment limitations, this research provides valuable insights into the potential of recycling cotton denim. Future work should explore advanced recycling techniques to improve quality and broaden application opportunities.