The authors update the current status of diagnostic and staging work-up and therapy of renal cell carcinoma (RCC). They first point out that the disease is increasingly discovered incidentally (about 30% of cases) when symptoms are absent. This, on average, has not led to a clear variation in stage distribution at first observation. It is not rare, however, to find very small lesions, for which differential diagnosis and particular therapeutic strategy are needed, because in some instances small lesions can give distant metastases. Hematuria remains the onset symptom in about 60% of cases where in about 20% of cases systemic symptoms or paraneoplastic syndromes are present. Distant metastases at presentation are still not rare, being observed in about 6-15% of patients. A review of diagnostic tools is then made, concluding that CT scan should be considered the most sensitive examination. The differential diagnosis with oncocytoma, angiomyolipoma and the so-called 'pseudo-tumors' is discussed in detail because these are the most frequently observed renal lesions out of RCC. Special attention is reserved for the diagnostic problems of renal cysts, suggesting that the Bosniak classification should be generally followed, and to the indications for fine-needle aspiration and biopsy which should be performed only in very selected cases. Minimal requirements for staging are indicated after a survey of the most common diagnostic methods. In treatment issues, the efficacy of lymph node dissection and adrenalectomy are discussed, concluding that the present body of data is still unable to clearly indicate that there is an absolute indication for extensive lymph node dissection whereas in selected cases partial nephrectomy may be a valid therapeutic option. Results of immunotherapy, cytotoxic therapy and their association are finally summarized as well as future prospects.