Currently, there are many options for the treatment of metastatic renal cell carcinoma (RCC). Being a mostly chemoresistant malignancy, renal cell carcinoma is usually treated with immunotherapy. These therapies are generally based on interleukin-2 (IL-2) or interferon alfa (IFN-alpha), or involve more novel techniques such as gene therapy. IL-2 is a biological agent that has been approved by the U.S. Food and Drug Administration and leads to durable remissions in a subset of patients with metastatic RCC. Patients presenting with a good performance status and without serious concomitant cardiac or pulmonary disorders should be considered for IL-2-based therapy as first-line treatment.