The extracellular matrix (ECM) is a dynamic and complex network of proteins and glycosaminoglycans that undergo continuous remodeling to maintain tissue integrity and function. ECM remodeling is a highly regulated process essential for tissue development, wound healing, and homeostasis. This chapter focuses on the molecular mechanisms underlying ECM remodeling, highlighting the roles of matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), and other proteolytic enzymes that control ECM degradation and reconstruction. These enzymes cleave structural components of the ECM, such as collagen, elastin, and fibronectin, facilitating the turnover and reorganization of the matrix. ECM remodeling is also influenced by cellular activities, including fibroblast-mediated synthesis of new ECM components and the deposition of proteins like collagen, which are critical for maintaining structural integrity. Aberrant ECM remodeling contributes to the pathophysiology of various diseases, including cancer, fibrosis, and cardiovascular disorders. In cancer, for example, excessive degradation of the ECM can promote tumor invasion and metastasis by altering tissue architecture and enabling cancer cells to migrate through weakened barriers. Conversely, in fibrotic diseases, excessive ECM deposition leads to tissue stiffening and organ dysfunction. The mechanical properties of the ECM, such as stiffness and elasticity, also play a crucial role in regulating cellular behavior, with altered ECM mechanics influencing cell adhesion, migration, and differentiation.