The use of surgically excised/mechanically fragmented dermal fat grafts by injection led to the use of suction-aspirated fat for autologous grafts by injection. Efforts to scientifically evaluate the fat survival began with a microscopic evaluation of the integrity of the aspirated fat in a series of patients. The next study consisted of injection of dye-stained fat into the abdominal skin/fat followed by removal and microscopic evaluation of the grafts from 3 months to 1 year later. Also, different sized cannulas for removal and different sized needles for injection of fat were used, with the abdominal skin/fat used as the recipient site. Studies were also done to compare washing versus nonwashing of the fat. These studies and 10 years of clinical evaluation and follow-up has led us to conclude that fat, properly aspirated, properly prepared, and properly injected, is an excellent and permanent substance for soft tissue augmentation.