The diagnosis of retroperitoneal fatty tumour is not extremely difficult provided that the possibility of its presence is kept in mind by the surgeon in all cases of distended abdomen in an apparently well-nourished patient. A careful clinical examination and a good excretory pyelogram are very important in the diagnosis. Surgical excision requires a considerable amount of patience and boldness on the part of the surgeon and is always gratifying, even if the tumour cannot be totally removed. Three cases of retroperitoneal tumour treated by us are presented. All three had had previous unsatisfactory treatment, the first two being incorrectly diagnosed and the third being inadequately excised. The pathology, diagnosis and treatment of these tumours are briefly discussed.