The clinical data have been compared with the biopsy results of 24 patients who died of dissecting aneurysm of the aorta. The clinico-anatomical data permit the authors to conclude that if dissection of the walls of the abdominal aorta takes place at the level of emerging renal arteries the dissecting aneurysm assumes the character of the renal disease with the typical pain syndrome resembling "renal colic". A number of symptoms are described typical for the dissecting aneurysm distinguishing it from the true kidney disease.