Obstructive uropathy caused by upper urinary tract fungal ball formation is an uncommon but well recognized clinical entity. The clinical course and management of an infant with unilateral fungal ball obstruction is described. Ultrasound and Tc-diaminotetraethylpentacetic acid (DTPA) renal scan contributed significantly to the diagnosis and management of this patient. Complete resolution of the obstruction was achieved by treatment with intravenous amphotericin B and oral 5-fluorocytosine. The clinical course and management of 35 patients described in the literature indicate that prematurity, use of broad spectrum antibiotics, prolonged hospital stay and the use of intravascular catheters are predisposing factors. The mortality rate is 34%. Young age, small size, the presence of candidaemia and withholding antifungal therapy are poor prognostic factors. A rational plan of treatment, extrapolated from the literature, is presented which may help to reduce the mortality rate in this condition.