We have carried out embolisation of malignant renal tumours using homogenised muscle in a number of patients. Since October 1974, this has been done 22 times; in six cases the tumour was inoperable. Pre-operative embolisation of resectable renal tumours makes the operative procedures easier and reduces operative risks in older patients. Haematuria, which can cause bladder obstruction, is considered a particular indication in the presence of an inoperable tumour. Tumour growth can be reduced or there may even be regression. There were no significant complications as a result of embolisation of renal tumours with autologous homogenised muscle.