A part from nephrolithiasis, renal involvement is rare in the course of Crohn's disease, particularly glomerulonephritis. On the other hand, while onset of Crohn's disease is strongly influenced by environmental and genetic factors, little is known regarding influence of these factors on extra intestinal manifestations. We report a familial case of glomerulonephritis that occurred in a 38-year old woman and her mother, 59 years old with a 7-year and a 37 year history of stenosing ileocolonic disease, respectively. Both of them developed peripheral oedema with nephrotic syndrome during the course of their Crohn's disease while they had no intestinal symptoms and were not receiving any maintenance therapy. Renal function was conserved in the former while the latter developed renal failure and had already small size kidneys on abdominal sonography. Thus, renal biopsy had been performed only in the former patient and had showed membranous glomerulonephritis. Investigations showed no other underlying disease than Crohn's disease. Through this report we emphasis possible genetic influence on extra intestinal manifestations, particularly glomerulonephritis, in Crohn's disease patients.