Nine cases of idiopathic constitutional subcutaneous fat atrophy in the cheek area during the years 1988-1992 were treated by the autologous transplantation of fat for purely aesthetic reasons. The fat graft suspension was obtained by the low-power aspiration technique with the use of a vacuum pump. The contour defects were initially overcorrected by approximately 50 percent more volume than required. The patients were followed up for 1.5 to 4.5 (mean, 3.5) years. Contrary to the experience of others, only the partial resorption of the transplanted fat occurred. This result was verified by six biopsy specimens obtained in the time range of 7 to 36 months after transplantation. The additional injections of fat were not necessary. Delicate tissue handling and the small total amount of fat transplanted by careful distribution in the recipient tissues are probably the factors responsible for the long-lasting improvement in these patients. As an experiment, suction of fat under -0.5 atm and -0.95 atm was performed in five patients undergoing abdominal liposuction. Aspiration under maximum negative pressure caused partial breakage and vaporization of the fatty tissue. The diameter of the fat cells in the remaining beads of fat was in all five cases mechanically distended and thus was larger than in the lipocytes extracted at -0.5 atm.