Adipose tissue is believed to constitute an ideal source of uncultured stromal stem cells. By optimizing the harvesting, storage, and transplantation of adipose tissue, long-lasting results can be obtained. Cell-assisted lipotransfer (CAL) is a novel approach to autologous fat transplantation in which adipose-derived stem cells are attached to the aspirated fat. The authors describe the cell processing methods, delivery systems, and clinical applications of CAL.