The patient was a 38-year-old woman diagnosed with nephrotic syndrome. Steroid pulse therapy and mizoribine was started in late October 2002 and continued for about 10 months, but no apparent therapeutic effect was obtained. During this period, the patient was diagnosed with nasopharyngeal carcinoma. As nephrotic syndrome did not improve, renal biopsy was performed and membranous nephropathy (MN) was diagnosed. After resection of nasopharyngeal carcinoma was performed, the urinary protein level decreased rapidly. Since MN caused by nasopharyngeal carcinoma is very rare, this represents an interesting case of malignancy-associated MN.