Primary hyperoxaluria (PH) is a metabolic autosomal recessive disease that causes an error in oxalate metabolism. In 1957, Archer et al(1) introduced the term primary hyperoxaluria. Two types are known. In type 1 the enzyme alanine glyoxylate aminotransferase , mostly made by the liver, is lacking.(2) This results in accumulation of oxalate in mesoderm tissue and increased excretion of oxalate in urine. In type 2 an increased excretion of L-glycerate in urine is found. The disease is characterized by hyperoxaluria, nephrolithiasis, nephrocalcinosis, and widespread tissue oxalate deposits. The term oxalosis was given by Chaplin(3) to describe deposits of calcium oxalate crystals in extrarenal tissue. Secondary forms of oxalosis also exist. These are caused by ingestion of substances that contain the oxalate ion or are metabolized to oxalate. Ingestion of excessive amounts of rhubarb and ethylene glycol can also induce oxalate toxicity. PH eventually leads to end-stage renal failure. In most patients this will occur in their teens in both types 1 and 2.(4,5) In recent decades, life expectancy has increased because of hemo- or peritoneal dialysis. In the past, kidney transplantations were carried out with minimal success because the enzyme alanine glyoxylate aminotransferase was lacking. Therefore, combined liver-kidney transplantation was recommended to accomplish a normal enzymatic activity for the metabolism of oxalate. 6 The earlier the kidney is transplanted, the less manifestations of systemic oxalosis will occur. 4 New deposits of oxalate may occur after transplantation in the allograft and/or other tissues.(7,8) In contrast, liver transplantation may cure the systemic storage disease and provide valuable quality of life.(4) The oxalate deposition is most pronounced in the kidney. Extrarenal deposits of calcium oxalate monohydrate are described in the bone, heart, ocular tissue, thyroid, lymph nodes, skin, walls of arteries and veins, brain, meninges, and salivary glands.(9-14) Deposition of calcium oxalate crystals in dentine and pulp have been described,(15-22) resulting in dental pain, tooth mobility, and external root resorption. A patient diagnosed with PH and clear oral manifestations of oxalosis is presented and the literature is reviewed.