After nephrectomy for renal cell carcinoma (RCC), a significant number of patients develop recurrent disease. In order to improve the prognosis of these patients, the role of adjuvant immunotherapy should be clarified; the appropriate selection of patients is especially crucial. For this purpose, the search for prognostic factors is important to identify at-risk patients. Known factors such as stage, grade, and microvascular invasion can be used for appropriate selection. Other molecular markers, such as cadherin-6 and G250 antigen, may become important. So far, adjuvant immunotherapy in RCC has not shown improved survival data, but the results may be hampered by inadequate recruitment and follow-up. Adequate selection of patients and the search for less toxic and more effective immunotherapy approaches are of importance. Therefore, the use of monoclonal antibody G250 or dendritic cell vaccinations, alone or together with cytokines, may be advantageous and is currently used. Today, adjuvant protocols are open for recruitment of patients to elucidate the important question as to whether this approach should be implemented in the treatment of RCC. In this article, an update is given in the field of adjuvant immunotherapy in patients with RCC.