Renal cell carcinoma (RCC) is characterized by an unpredictable clinical course. Therefore, prognostic factors are urgently needed. So far, clinical staging is the most powerful predictor of the progression of RCC. A better understanding of cell biological and molecular changes associated with the development of this disease is urgently needed. Recently, application of a number of these have been tested. Whereas some do not seem to have prognostic value over the available classical prognostic markers, quantitative nuclear morphometric measurement and assessment of cadherin-mediated adhesion complexes (catenin immunohistochemistry) have opened new prospectives.