A 4 month-old premature infant having received prolonged intensive care for necrotizing enterocolitis and Pseudomonas infection, developed anuria with intrapyelic fungus ball developed in a congenital single kidney. Review of the literature found 19 similar cases and emphasized the difficulty of an early diagnosis and the usefulness of renal ultrasonography for its detection. Moreover the opportunity to treat premature neonates carrying candida albicans with IV amphotericin B and flucytosine before the occurrence of an uneasy treatable urological obstacle in discussed.