Ulcerative colitis is rarely associated with immunoglobulin A nephropathy (IgAN). The development of IgA nephropathy complicates further the clinical course of patients with ulcerative colitis. A 72-year old man with a 30-year history of ulcerative colitis requiring colectomy and modest renal insufficiency secondary to complications of nephrolithiasis and renal artery stenosis developed glomerular hematuria, proteinuria and progressive renal failure. Percutaneous kidney biopsy revealed IgAN with extensive glomerular and interstitial sclerotic changes. After resection of a chronically infected ileo-rectal pouch, renal function improved, while hematuria and proteinuria gradually disappeared without specific treatment of the IgAN. The manifestations of IgAN complicating ulcerative colitis can be improved with effective treatment of the bowel disease even when there are extensive sclerotic changes in the kidneys.