Membranous glomerulonephritis (MGN) is the main cause of nephrotic syndrome in adults and is usually idiopathic. We report a case of nephrotic MGN associated with a myelodysplastic syndrome (MDS) in a 43 year old man. The initial treatment consisted of oral corticosteroids (1 mg/kg/day). Within 3 months proteinuria decreased from 22.4 g/day to 3.96 g/day and the blood cell count was normalized. Renal biopsy disclosed type I MGN. Ponticelli's protocol was started with a favorable effect: negative proteinuria, normal blood cell count and normal bone marrow cellularity. The association between MGN and MDS is quite rate. The possible links between the two conditions are reviewed.