Looking at the most frequent urological tumors kidney cancer has the worst prognosis. Primary therapy consists of operative tumor removal in most cases. A tumor cutoff between 4 and 5 cm represents the turn towards a significant risk for postoperative tumor relapse. In those patients neoadjuvant or adjuvant therapy would be indicated. However, no phase III trials on neoadjuvant therapy of kidney cancer have been published in the literature. In contrast, five phase III trials on adjuvant therapy of kidney cancer have been published. In four trials interferon-alpha and/or interleukin-2 were applied. None of these trials had a positive outcome. Moreover, adjuvant cytokine therapy was associated with significant side effects in 30% of patients. In the fifth trial an autologous tumor cell vaccine (Reniale) demonstrated an improvement of progression-free survival and overall survival. Also, there were less than 1% side effects. Results from active trials investigating a combination of interleukin-2, interferon-alpha and 5-FU, or a heat shock protein vaccine or an antibody are awaited soon. New trials are testing tyrosine kidney inhibitors such as sunitinib and sorafenib.