A critical retrospective evaluation of four cases of xanthogranulomatous pyelonephritis (XPG) treated between 1966 and 1980. Incidence was 1.93%. Age range was from 1.5 and 24 months. Interval since first symptoms to diagnosis was between one and 14 months. Clinical presentation was nonspecific in two and urinary symptoms in the rest, abdominal mass present in all, the fourth had an onset similar to an acute leucosis. There were was a grossly dilated pelvis and calices in two patients and nonfunctioning kidney in the others, one with multiple calculi. Ureteral stenosis was present in two and three showed a vesiureteral reflux grade IV. Urinculture yielded E. coli and Proteus mirabilis. In all cases diagnosis was confirmed by macro and microscopic examination. Nephrectomy was effectively cure in all four children. All patients are well at the end of follow-up, between one and four years.