We report a case of Castleman's disease of multifocal plasma-cell type revealed by a severe general weakness, associated to a nephrotic syndrome with renal failure. The characteristic aspects of lymphoid hyperplasia with hyalinization of follicles and interfollicular vascular proliferation were observed in mesenteric lymph nodes, the spleen was involved by an infarcted localisation of Castleman's disease. The glomerular lesions were consistent with a proliferative mesangial glomerulonephritis. The removal of the spleen and of the mesenteric nodes involved by the disease, associated with a steroid course was curative. The nephrotic syndrome appears to be etiologically related to the presence of the Castleman's tumor. The removal of the tumor relieves the proteinuria and the renal failure as in other cases reported in the literature.