A brief discussion of the epidemiology and aetiology of renal carcinoma is followed by a description of the clinical features. Attention is drawn to the significance of haematuria, especially microhaematuria and the para-neoplastic syndrome (toxic and endocrine tumour effect) in establishing an early diagnosis. Intravenous urography still remains the most important diagnostic procedure, whilst renal angiography is indispensable for the precise definition of tumour localization and extension. It is possible to solve most of the problems of differential diagnosis (primarily distinguishing between cyst and tumour) by means of renal angiography and sonography. Therapy is still based on surgical treatment, transperitoneal, "radical" tumour extirpation leading to an improvement in the results in about 15% of the cases, especially in stages III and IV. A 5-year survival rate may be expected in 60 to 70% of stage I and stage II cases, in about 40% of stage III and only a few percent of stage IV cases. Cytostatic therapy offers no improvement in results at the moment. Irradiation before and after surgical treatment, as well as hormonal medication produces a modest rise in the 5-year survival rate. The decisive factor is early diagnosis of renal carcinoma, because about half of all patients show evidence of metastasis already at the first examination.