Liver transplantation has been demonstrated to be a successful therapeutic modality for patients with end-stage liver disease. The high rate of survival for an otherwise terminal condition has resulted in significant expansion of the indications and diseases treated by this procedure, and is hampered only by the limited numbers of organs available for transplantation. Efforts in clinical and laboratory medicine should be directed to identify candidates who would benefit most from this procedure, to provide better means for accurate assessment of liver reserve and the appropriate timing for transplantation, to identify quality liver grafts that would have the potential to tolerate cold preservation and reperfusion injury, and to assist in accurate monitoring of graft function immediately after transplantation. The aim of this manuscript is to describe the existing pathways for clinical and laboratory assessment of pretransplant residual liver function, the donor liver graft, and immediate posttransplantation function.