A 53-year-old woman was admitted with complaints of edema in the lower legs. The patient had developed polyarthralgia in 1982 and had been treated with D-penicillamine and prednisolone under the diagnosis of rheumatoid arthritis. She then had developed sclerosis of skin as well as dry eyes and dry mouth. In November 1987, bucillamine treatment had started and proteinuria had appeared in February 1988. Her blood showed hypoproteinemia and was positive for anti-Scl-70 antibody test and for anti-SS-A antibody test. The skin biopsy and labial salivary gland biopsy revealed the increased collagen fibers in the subcutaneous tissue and the round cell infiltration around the salivary ducts. We diagnosed her as progressive systemic sclerosis (PSS) with Sjögren's syndrome (SjS) complicated by nephrotic syndrome. Subsequently a renal biopsy was performed. There were the granular deposition of IgG and complements in the glomerular capillary wall and electron dense deposits in the subepithelial region. These findings suggested that she had membranous nephropathy. Since such a renal lesion was rarely observed in PSS and SjS, it was highly probable that bucillamine induced the nephropathy. The bucillamine treatment was discontinued about 2 months after the nephrotic syndrome had developed. However, the nephrotic syndrome has continued for additional 8 months. Thus it is concluded that the renal damage is one of the important side effect caused by bucillamine.