Although percutaneous ultrasound-guided technique is currently a common practice, the use of ultrasound for the purpose of guidance during surgery has not been widely practiced. Over a period of 10 years, we performed operative ultrasonography in 2,314 operations. In 321 of these operations, operative ultrasound guidance was performed for direct assistance of various surgical procedures, particularly during operations on the brain and spinal cord, liver, pancreas, and kidney. Procedures guided by operative ultrasound were classified into the following categories: intraoperative needle placement for fluid aspiration (n = 38), agent injection (n = 14), catheter introduction (n = 27), biopsy (n = 57), surgical tissue dissection for incision (n = 48), resection (n = 82) of organs, and extraction (n = 55) of stones or foreign bodies. Operative ultrasound guidance facilitates various surgical procedures and is considered a useful modality for reducing operative complications, shortening operating time, performing otherwise impossible procedures, and, at times, developing new surgical operations.