Urological complications are not uncommon in Crohn's disease (CD). The most common manifestations are renal stones, enterovesical fistulas, and ureteral obstruction, but renal parenchymal disease has rarely been reported. IgA nephropathy, the most common form of primary glomerulonephritis, is usually isolated, but can be sometimes associated with chronic extrarenal disorders such as inflammatory bowel disease. We describe a case of 36 year-old man with CD associated with IgA nephropathy. He was diagnosed as CD 6 years ago and at that time, isolated proteinuria was observed. He presented recurrent proteinuria and elevation of creatinine level while he had been managed well with mesalamine and azathioprine. The renal biopsy was performed and IgA nephropathy (type IV) was diagnosed. Strict blood pressure control with angiotensin converting enzyme inhibitor and calcium channel blocker resulted in clinical improvement and normalization of serum creatinine level.