A 65-year-old woman with bilateral renal parenchymal malakoplakia and renal vein thrombosis had severe azotemia, bilaterally enlarged kidneys, urinary tract infection, and sepsis. Angiographic studies demonstrated left renal vein thrombosis. A percutaneous kidney biopsy specimen showed the characteristic Michaelis-Gutmann bodies. After therapy with fluid replacement, antibiotics, and long-term anticoagulation, kidney function improved and both kidneys decreased in size. We suggest that, with adequate treatment of urinary tract infection and correction of potential insults to the kidney, progression of this peculiar disease can be prevented.