Living donor transplantation in children has proven to be safe and effective for both donors and recipients and has helped make death on the waiting list a less common event. Since its introduction in 1990, many of the technical and ethical issues have been addressed, and the procedure is generally applied. The development of left or right hepatic lobectomy for adult-to-adult living donor liver transplantation has been slower. Because of the ongoing shortage of cadaver livers suitable for transplantation, adult-to-adult living donor liver transplantation has been performed at a number of centers. Although early results appear encouraging, sufficient data are not available to ascertain donor morbidity and mortality rates. There is general consensus that the health and safety of the donor is and must remain central to living organ donation. The practice guidelines put forth here are intended to underscore this issue, as well as provide a mechanism to document outcomes as the area develops.