Membraneous nephropathy (MN) is the most commonly occurring nephrotic syndrome in adults as well as the most common paraneoplastic nephropathy associated with solid tumors, and it is mostly associated with gastrointestinal system and lung carcinomas. Accurate diagnosis is important as the treatment of paraneoplastic glomerulonephritis is very varied from that of idiopathic ones. In the current report, a case of a patient that was referred with proteinuria and edema and was diagnosed with lung cancer, and responded markedly to treatment of malignancy, with improvement of MN, is presented. Active cancer is present in all patients with paraneoplastic MN. In numerous patients, the paraneoplastic MN and cancer diagnoses are made within one year of each other. The treatment of paraneoplastic syndromes is usually associated with the treatment of primary malignancy. There are conflicting data on which treatment modality is more suitable. In conclusion, further studies are required in order to determine the actual incidence of cancer in patients with nephropathy, explain the physiopathological association between cancer and nephropathy and to determine the most suitable treatment approaches.