Long-term survival of relapsed Wilms' tumor patients is about 40% to 70%. Modern second-line treatment consists of either (a) salvage chemotherapy+/-radiation therapy (CT) or (b) chemotherapy followed by high-dose chemotherapy and autologous hematopoietic stem cell rescue (ASCR). Here, we conduct an individual patient data meta-analysis on 100 patients collected from 6 studies to determine characteristics that predict survival in relapsed patients who received ASCR therapy. We compare these results with survival data on 118 CT treated patients from 2 recently published studies. Four year overall survival among the combined ASCR treated patients was 54.1% (95% CI: 42.8-64.1%). The ASCR patients who only relapsed in the lungs had higher 4-years survival rates 77.7% (58.6% to 88.8%) than those who relapsed in other locations and/or suffered multiple relapses 41.6% (24.8% to 57.6%). Although lung-only relapse is considered a favorable prognostic factor, there was no clear advantage for the patients treated with salvage chemotherapy. Four-year survival rates among stage I-II patients were about 30% higher with CT than ASCR, but the 2 were comparable for stage III-IV patients. These findings suggest salvage chemotherapy is typically the better choice for relapsed Wilms' tumor patients, ASCR could be considered for stage III-IV patients with a lung-only relapse.