Summary: Grafted fat has many attributes of an ideal filler, but the results, like those of any procedure, are technique dependent. Fat grafting remains shrouded in the stigma of variable results experienced by most plastic surgeons when they first graft fat. However, many who originally reported failure eventually report success after altering their methods of harvesting, refinement, and placement. Many surgeons have refined their techniques to obtain long-term survival and volume replacement with grafted fat. They have observed that transplanted fat not only adjusts facial and body proportion but also improves surrounding tissues into which the fat is placed. They have noted not only the improvement in the quality of aging skin and scars but also a remarkable improvement in conditions such as radiation damage, chronic ulceration, breast capsular contracture, and damaged vocal cords. The mechanism of fat graft survival is not clear, and the role of adipose-derived stem cells and preadipocytes in fat survival remains to be determined. Early research has indicated the possible involvement of more undifferentiated cells in some of the observed effects of fat grafting on surrounding tissues. Of particular interest is the research that has pointed to the use of stem cells to repair and even to become bone, cartilage, muscle, blood vessels, nerves, and skin. Further studies are essential to understand grafted fat tissue.