The sixth case of this rare childhood disease has been successfully treated by nephrectomy. Usually encountered in women 40 to 60 years of age, xanthogranulomatous pyelonephritis is a chronic suppurative renal infection characterized by the presence of granulomas, abcesses, and lipid-laden foam cells. Proteus vulgaris or Staphylococcus aureus appears to be the causative organism. On intravenous pyelography there is an obstructed nonfunctioning kidney with a stag-horn calculus. Angiography reveals decreased vascularity, in contrast to renal adenocarcinoma. In children the lesion presents as a localized mass producing displacement or compression of adjacent renal parenchyma. Wilm's tumor or neuroblastoma is usually misdiagnosed before surgery and is difficult to differentiate from xanthogranulomatous pyelonephritis at the operating table. Nephrectomy has effectively cured all six children.