A 37-year-old man developed nephrotic syndrome and renal insufficiency in 1986. He had ĸ-light-chain protein both in serum and urine. A renal biopsy showed nodular glomerulosclerosis with deposition of ĸ-light-chains in the mesangial area, compatible with light-chain nephropathy. Thereafter, he was treated with steroids and melphalane and the light-chain protein disappeared from both the urine and serum. Although his moderately impaired renal function maintained stable levels for over 10 years, he was diagnosed as having renal cell carcinoma in 1998, and a right nephrectomy was performed. Histopathological examination of a portion of the removed kidney, unaffected by carcinoma, showed mild mesangial proliferation, and both the nodular lesions and light-chain deposits were no longer observed. These observations suggest that an established nodular glomerular lesion may be reversible.