A 56-year-old man presented with peripheral monocytosis and massive nephrotic syndrome. He was diagnosed as having chronic myelomonocytic leukemia and membranous glomerulonephritis. He received prednisone, chlorambucil and hydroxyurea, but the nephrotic syndrome persisted. Seven months after diagnosis, he was started on cyclosporin A; 1 month later he developed acute renal failure due to radiolucent bilateral renoureteral stones. His kidney function recovered after placing ureteral catheters and urine alkalization. Afterward, he was given mycophenolate mofetil, and proteinuria decreased to subnephrotic levels (1 g/24 hours). This case highlights 2 severe renal complications in this type of leukemia. To the best of our knowledge, there are only 2 previous cases of glomerulonephritis, histologically proven, associated with chronic myelomonocytic leukemia. On the other hand, reversible acute renal failure due to radiolucent bilateral renoureteral stones has never been reported. Also, as far as we know, mycophenolate mofetil was successfully used here for the first time for treating glomerulonephritis-related chronic myelomonocytic leukemia.