The purpose of the present study was to determine the position, dimensions and structure of the left kidney, the urinary bladder and the urethra in cattle by use of ultrasonography. The left kidney, the urinary bladder and the urethra of 12 healthy, Swiss Braunvieh cows were examined transrectally using a 5.0 MHz linear transducer 10 times within two weeks. The lobulation of the kidney in cattle could be visualized ultrasonographically. The echogenicity of various renal structures differed. The renal cortex was hyperechoic in comparison to the relative hypoechoic renal medullary pyramids. The urinary bladder was always visible but its diameter varied greatly. The vertical diameter of the left kidney was 6.2 +/- 1.0 cm in the region of the renal hilus. In 7 cows the thickness of renal cortex and medulla was between 2.0 and 2.3 cm. The diameter of the renal sinus varied from 1.1 to 2.5 cm. The interassay coefficients of variation of the variables measured varied between 8.5 and 16.5%. It was concluded that the ultrasonographic values determined in this study can be used as references for the diagnosis of morphologic changes in the bovine left kidney.