Renal biopsy of a 70-year-old woman with clinical features of rapidly progressive glomerulonephritis revealed nodular glomerulosclerosis with conspicuous crescent formation. Other peculiar findings were the presence of many mesangiolytic cystic lesions and multinucleated giant cells in the cystic lesions. By immunofluorescent microscopic study, lambda light and gamma heavy chains were found in mesangial nodules, Bowman's capsule and the tubular basement membrane. Multiple myeloma was diagnosed by bone marrow examination. Autopsy performed two months later revealed systemic deposition of lambda light and gamma heavy chains, and fairly advanced nodular glomerulosclerosis. Most of the glomerular nodular lesions had a lamellar structure. Amyloid was not found. The high incidence of both mesangiolytic lesions in the biopsy specimen and laminated glomerular nodules in the autopsy material supports the previously proposed pathogenetic relationship of these two findings.