The role of aggressive surgery for metastatic renal cancer in the era of biological therapy is not clear. Therefore, we reviewed 17 patients who, between February 1987 and August 1990, underwent surgical resection of residual masses following initial response to interferon-alpha-based therapy. Viable tumor persisted in 15 patients (88%), whereas only inflammatory response was detected in 2. Of the patients 11 (65%) remained disease-free at a median of 12 months postoperatively (range 5 to 29), with an overall median survival of 26 months (range 6 to 34) from treatment initiation. These data suggest that surgery may be of therapeutic benefit in select patients with renal cell carcinoma who do not meet traditional criteria for surgical resection. Prospective trials are being performed to determine whether there is a role for aggressive surgical resection of persistent disease in patients with advanced renal cell carcinoma who have previously responded to interferon-alpha-based therapy.