ABSTRACT Application of ultrasound in pain medicine is a rapidly growing medical field in interventional pain management. Ultrasound provides direct visualization of various soft tissues and real-time needle advancement and avoids exposing both the health care provider and the patient to the risks of radiation. The machine itself is more affordable than a fluoroscope, computed tomography scan, or magnetic resonance imaging machine. In the present review, we discuss the challenges and limitations of ultrasound-guided procedures for pain management, anatomy, and sonoanatomy of selected pain management procedures and the literature on those selected procedures. (Reg Anesth Pain Med 2009;34: 458Y474) Application of ultrasound in pain medicine (USPM)is a rapidly growing component of interventional pain management. Traditionally, interventional procedures for pain management are performed either according to the description of surface landmarks or with imaging guidance such as fluoroscopy and computed tomography (CT) scan. In the last 5 years, there has been a tremendous growth in interest in USPM, as evidenced by the remarkable increase in the literature on ultrasound-guided injections. A search of the MEDLINE database revealed only 3 publications of ultrasound-guided or ultrasound-assisted injection techniques (excluding perioperative and various intraarticular, interlaminar, and trigger-point injections) between 1982 and 2002,1Y3 but there have been 42 publications since 2003. The first objective of this review was to describe and summarize the anatomy and sonoanatomy that are relevant to those specific interventional techniques. The second objective was to describe the limited reports and feasibility data published in the literature on the selected USPM procedures.