A case of oxalosis in a 20-month-old female with edema, anemia, pyelonephritis with nephrocalcinosis, acidosis, oliguria and uremia is described for the first time in Turkish literature. Diagnosis was established by examination of renal tissue obtained by immediate post-mortem needle aspiration technique. Clinical and microscopic features, as well as the pathogenesis of the disease and a review of the pertinent literature, are presented. Evidence suggests that this metabolic disorder of glyoxylate metabolism results in the precipitation of calcium oxalate crystals which can easily be demonstrated by kidney biopsy technique and the value of this technique in the diagnosis of the disease is worth emphasizing. Other points of interest are the consanguinity of the parents, which is consistent with the recessive transmission of the disease, and elevated uric acid levels in the serum.