Between 1999 and 2004, 11 patients with metastatic renal cell carcinoma (RCC) underwent non-myeloablative stem cell transplantation (NST) with conditioning using fludarabine-based regimens in two institutions of Korea. Among 11 patients, only one patient showed partial response (response rate: 9%), three showed stable disease, and six progressive disease. Three patients developed acute graft-versus-host disease (GVHD), and among them, one developed grade III acute GVHD which caused early death at day 60 after transplantation, and this patient showed partial response at day 30. Six patients developed chronic GVHD, three limited, and three extensive GVHD, respectively. Survival after one yr was 18% in transplanted patients. Median overall survival for entire cohort was 4.3 months. Eight patients died from progressive disease and three (27%) from treatment-related mortality. Only one patient survived 51.2 months after NST with slowly progressive disease. This patient received donor lymphocyte infusion three times after NST and achieved complete donor chimerism. NST does not lead to durable response and prolonged overall survival in the majority of patients with RCC in our series.