Miniature transducer-containing catheters (6 French 20 MHz and 9 French 12.5 MHz) have been inserted into the urethra, urinary bladder, ureter and renal pelvis. Real-time 360 degrees cross sectional ultrasound images were obtained delineating a variety of normal and abnormal structures in both animal models and humans. With this approach it was possible to measure wall thickness as well as adjacent external structures such as blood vessels, lymph nodes and muscle. It was possible to diagnose a variety of abnormalities including embedded stones in the ureter and renal pelvis, crossing blood vessels producing compression of the ureter and tumors within the urinary bladder and ureter. In addition, these transducer-containing catheters show promise in assisting in tumor staging and biopsy guidance. These specially developed transducer-containing catheters, intended originally for placement in blood vessels, show great promise in becoming important new tools in a wide variety of non-vascular lumina and surgically created openings in many areas of the body. From our initial results we can already predict that non-vascular endoluminal ultrasound will assume an important role in the evaluation of a variety of urologic abnormalities.