A 51-year-old man was hospitalized and operated on for gastric carcinoma with widespread metastases and died two months after the laparatomy and biopsy examination. Two years prior to the operation, he deveoped nephrotic syndrome. Anaplastic carcinoma, linitis plastica form, of the stomach was found in the tumor biopsy examination and at autopsy. Light and electron microscopical studies of the kidney biopsy specimen taken at laparatomy confirmed the presence of membranous glomerulopathy. An immunologic basis of the concomitant appearance of malignant neoplasms and nephrotic syndrome is possible, based on reported cases. There is also a possibility that renal damage occurs more commonly in malignant neoplasms, but is not recognized clinically.