The repair of soft tissue defects, particularly after trauma and oncologic surgery, represents a major clinical challenge. While current reconstructive procedures can move soft tissue from other areas of the body, there remains an unmet need for new modalities that are less invasive and more precise. Adipose tissue is the key component necessary for soft tissue reconstruction. This review will discuss the discovery and potential of adult stem therapies in the regeneration of adipose tissue. Adipose-derived stem cells (ASCs), are being examined as cell delivery systems for soft tissue reconstruction. In addition to a further understanding of the biology of ASCs, appropriate biomaterials (e.g., cell delivery vehicles), rapid expansion of stem cells using bioreactors, and suitable animal models for adipose tissue engineering are needed for successful stem cell therapies, and will be discussed in this review. Clinical studies with ASCs are being conducted in Europe and Asia and will be described.