Patients with metastatic renal cell carcinoma continue to present a therapeutic challenge. Current therapeutic approaches involve surgery and various types of immunotherapy. The rationale for this latter form of therapy include the observations of spontaneous tumor regression, the presence of a T-cell-mediated immune response, and the tumor responses observed in patients receiving cytokine therapy. Analysis of prognostic factors in these patients demonstrates that clinical responses occur most frequently in individuals with good performance status. The cytokines interleukin-2 (IL-2, aldesleukin [Proleukin], interferon-alfa (Intron A, Roferon-A), or the combination produce responses in 15% to 20% of patients. Randomized trials suggest that administration of interferon-alfa may result in a modest improvement in median survival. Investigation of the molecular genetics of renal cell carcinoma and the presence of T-lymphocyte immune dysregulation have suggested new therapeutic strategies. Further preclinical and clinical studies investigating inhibitors of angiogenesis or pharmacologic methods to reverse immune dysregulation are ongoing. Therapeutic results in patients with renal cell carcinoma remain limited, and investigational approaches are warranted.