In 59 patients having non-operable malignant renal tumours, palliative trans-catheter embolization was performed. In 42 of them follow-up observations were realized over 18 months. The average survival rate was then 43% of cases. Local tumour growth was documented in 9 patients (23%) due to recanalization of the embolized arteries (13%) and to non-occluded collateral vessels (10%). The choice of suitable embolizing materials mainly influences the therapeutic result: Oily contrast labeled amino-acid Ethibloc is considered to be the material of choice for safe application and reliable vascular distribution causing persisting occlusion of the renal arteries.