Two cases of oxalosis in infancy are reported, the diagnosis and therapy are discussed and the world literature reviewed. Oxalosis in infancy is a rare condition, probably most frequently caused by a fulminant form of the autosomal recessive type I primary hyperoxaluria. It presents symptoms of renal failure in early infancy. This is progressive and usually causes death within three months after the onset of symptoms. The diagnosis can be suspected after simple procedures (abdominal roentgenogram, urinary tract ultrasonography) and confirmed by urine/plasma analysis and kidney biopsy/bone marrow aspiration. An exact diagnosis is important since it has consequences concerning genetic counseling and treatment. Dialysis and transplantation may be useful in secondary oxalosis, but until now they are hard to justify in infantile primary oxalosis. In primary hyperoxaluria (type I), pyridoxine therapy gives hopeful results before the onset of oxalosis, but unsatisfactory results after the onset of oxalosis.