Combined liver-kidney and kidney-only transplantation outcomes in primary hyperoxaluria (PH) are described. Strategies for the selection of type and timing of transplantation and pretransplantation and posttransplantation management are reviewed. Records were reviewed for 16 patients with PH who received 9 liver-kidney and 10 kidney-only transplants. Plasma oxalate values declined from 61 +/- 42 micromol/L pretransplantation to 9 +/- 6 micromol/L 1 month after transplantation in liver-kidney transplant recipients and 92 +/- 19 to 9 +/- 5 micromol/L in kidney-only transplant recipients. In most liver-kidney transplant recipients, hyperoxaluria persisted for 6 to 18 months after transplantation. Follow-up was 3.5 +/- 4.1 years in liver-kidney and 4.5 +/- 6.3 years in kidney-alone transplant recipients. Patient survival rates were 78% for liver-kidney and 89% for kidney-only transplant recipients. No hepatic allografts were lost. Three of 9 liver-kidney and 6 of 10 kidney-alone transplants lost renal allograft function. In those with functioning kidneys, renal clearance was 45.1 +/- 19.5 mL/min/1.73 m(2) in liver-kidney transplant recipients and 49.5 +/- 26.1 mL/min/1.73 m(2) in kidney-only transplant recipients at last follow-up. Kaplan-Meier 1-, 2-, 3-, and 5-year renal allograft survival rates for patients undergoing transplantation after 1984 were 78%, 78%, 52%, and 52% in liver-kidney transplant recipients and 86%, 71%, 54%, and 36% in kidney-only transplant recipients. Simultaneous grafting of liver and kidney after the development of renal insufficiency is recommended for the majority of patients with PH type I (PH-I). Kidney-alone transplantation is recommended for those with pyridoxine-responsive type I disease because pharmacological therapy allows favorable management of oxalate production in this situation. Kidney-alone transplantation also is recommended for PH type II (PH-II). This disease is less severe than PH-I, and it is currently unknown whether liver transplantation will correct the metabolic defect responsible for PH-II.