Thirty-one patients with disseminated melanoma or renal cell cancer (RCC) who had a limited relapse or persistent disease after a partial or complete response to interleukin-2 (IL-2)-based immunotherapy underwent resection of progressing tumors or residual sites of disease. There were no surgery-related deaths. The median time to disease progression after resection for patients with RCC (n = 16) and melanoma (n = 15) was 11 and 5 months, respectively. All patients with melanoma had tumor progression within 10 months of surgery. Seven of 16 patients with RCC were free of tumor progression 4 to 44 months after surgery. Three of 12 patients with RCC rendered disease-free by surgery remain disease-free after 2 years. These data suggest that surgical resection is a reasonable option in selected patients who have a relapse after responding to IL-2-based immunotherapy. Although this retrospective study could not determine the relative survival benefits of surgery and immunotherapy, it showed that resection of metastatic disease after a response to immunotherapy can result in significant disease-free survival in patients with RCC but not melanoma.