Purpose Of Review: Primary hyperoxaluria type 1, the most common form of primary hyperoxaluria, is an autosomal recessive disorder caused by a deficiency of the liver-specific enzyme alanine:glyoxylate aminotransferase. This results in increased synthesis and subsequent urinary excretion of the metabolic end-product oxalate and the deposition of insoluble calcium oxalate in the kidney and urinary tract. As glomerular filtration rate decreases due to progressive renal involvement, oxalate accumulates and results in systemic oxalosis. Recent Findings: Diagnosis is still often delayed. It is mainly established on the basis of clinical and sonographic findings, urinary oxalate ± glycolate assessment, and DNA analysis. Summary: Following specific conservative measures, the ultimate management is based on organ transplantation. Correction of the enzyme defect by liver transplantation should be planned before systemic oxalosis develops to optimize outcomes and may be either simultaneous (immunological benefit) or sequential (biochemical benefit) liver-kidney transplantation depending on disease staging, facilities, and access to deceased or living donors. Allograft and patient survival currently approaches that of transplant patients with kidney transplantation alone and with other diseases requiring combined liver-kidney transplantation. In addition, this strategy has also provided significant improvement in both quality of life and statural growth. © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins.