Facial aging involves changes in skin, bones, and soft tissue. Understanding these changes is crucial for effective facial rejuvenation. Autologous fat grafting, which uses a patient’s own fat, is a preferred method for soft tissue augmentation due to its compatibility, low cost, and minimal patient morbidity. Fat grafting with millifat and microfat may be used to improve contour in any area treatable by nonautologous injectable fillers, including the temples, forehead, upper and lower orbits, cheeks, perioral region, nasolabial fold, jawline, and chin—with the benefit of a more natural contour and integration with native tissue. This chapter describes a new technique of fat grafting for the face called injectable tissue replacement and regeneration that specifically addresses the different anatomic compartments of the face with volume loss and the potential of the adipose-derived stem cells into the skin rejuvenation.