In conclusion, the antimutagenicand antimicrobial activity of spent coffee found in this study suggests that this by-product could be considered as a potential food ingredient for enhancing functional properties and extending the shelflife of foods, or also for pharmaceutical and cosmetic purposes. Although further research is needed to study the stability of compounds in a food matrix and while undergoing industrial processes, the results support the idea that spent coffee is an accessible, sustainable, and major source of bioactive compounds with potential health benefits.