PURPOSE: To compare ultrasound (US) with computed tomography (CT) as a guidance modality for percutaneous interventional procedures. MATERIALS AND METHODS: A database of abdominal interventional procedures was reviewed for the 6 months preceding and 6 months after the opening of a dedicated US interventional suite. Changes in the number and type of procedures performed, room time, number of needle passes, and complication rates were calculated. RESULTS: In the first 6 months, 305 interventional procedures (138 tissue biopsies and 167 fluid aspirations) were performed (CT guidance in 87% [n = 120] and 95% [n = 159], respectively). In the 6 months after installation of the suite, 395 procedures (195 tissue biopsies and 200 fluid aspirations) were performed (US guidance in 76% [n = 148] and 34% [n = 67], respectively). The largest increase in US utilization was for guidance of tissue biopsies, rising from 6% (18 of 305) to 37% (148 of 395) of all procedures. Room time was significantly less for US-guided procedures (mean US room time, 77 minutes +/- 33 [1 standard deviation]; mean CT room time, 99 minutes +/- 38; P < .0001). CONCLUSION: US guidance often allows performance of quicker, more accurate procedures than does CT guidance, probably because of its real-time capabilities.