This chapter focuses on the crucial role of the extracellular matrix (ECM) in autologous fat grafting, a rapidly growing field driven by technological advancements and the increasing demand for minimally invasive procedures. It provides a clear overview of ECM components and their interactions with adipose tissues, emphasizing how these dynamics influence the survival, integration, and longevity of fat grafts. The chapter highlights the role of the ECM in supporting angiogenesis and adipogenesis, which are vital for successful tissue regeneration. It also explores the potential of acellular adipose matrix (AAM) in reconstructive surgery and tissue engineering, underscoring the importance of future research focused on refining ECM-based materials and techniques to improve clinical outcomes.