An 81-year-old woman was admitted for leg edema. She was found to have membranous glomerulonephritis with advanced gastric cancer after renal biopsy and endoscopic examination. Serum albumin was 1.4 g/dL and total protein was 4 g/dL on admission. After albumin was administered, distal gastrectomy was performed. Albumin administration continued post-operatively. The post-operative course was unremarkable and she was discharged on post-operative day 19. Six months after the operation, serum albumin gradually increased and uric protein volume decreased. Possible remission of membranous glomerulonephritis with gastric cancer can be expected after gastrectomy but careful perioperative management is required.