Ultrasound has moved to the forefront of interventional radiology because o
f its incredible versatility as a real-time guidance method. Ultrasound has
proved to be faster, less expensive, and more accurate than CT for the gui
dance of many interventional procedures. Biopsies of many structures and or
gans that were previously considered impractical or unsafe, including biops
y of the spleen, lung, soft tissue, bone, hepatic cavernous hemangioma, and
biopsy through ascites or bowel, are now being performed with a high degre
e of safety and accuracy. This article updates the radiologist on the state
-of-the-art in ultrasound-guided intervention at the turn of the century.