A 70-year-old man with advanced obstructive nephropathy began to hemorrhage from the bladder after decompression with a Foley catheter. Manifestations of encephalopathy appeared after continuous irrigation with 1% alum for 2 days and were associated with elevated serum aluminum concentrations. Repeated treatments with deferoxamine and hemodialysis accomplished some aluminum removal, but the patient succumbed to bronchopneumonia. Brain aluminum content was not excessive at autopsy. A literature review suggests that intact renal function is essential to rapid disposal of a parenteral aluminum load and indicates that most reported instances of encephalopathy after alum irrigation have occurred in patients with compromised renal function. We conclude that alum should not be employed as a bladder irrigant in patients with acute or chronic renal failure.