The results of ultrasonography recordings carried out urgently in 12 patients after renal trauma are used by the authors as a basis for outlining the ultrasonography features discovered in post-traumatic renal lesions, and for discussing the value and place of this examination in overall investigations of these lesions. Ultrasonography findings are compared with those of intravenous urography, and in certain cases with those of arteriography. Ultrasonography appears to be indispensable in many cases in order to confirm intravenous urography results, to complement them, and possibly to make up for their deficiencies. It is of particular value in 2 conditions: a) renal artery thrombosis, in which case it is the only examination capable of supplying information on the parenchyma, b) benign renal contusions which may not appear on intravenous urography.