[Problem]Provided are: an ultrasound-guided puncture assist device that is capable of preventing occurrence of operational mistakes or the like when a nerve block or vascular puncture is performed under ultrasonography, an ultrasound-guided puncture method using the ultrasound-guided puncture assist device, and the like.[Solution]An ultrasound-guided puncture assist device with an object of preventing narrowing or the like of a puncture target site for a nerve block or vascular puncture under ultrasonography to thereby assist the puncture by comprising a pulling mechanism for pulling the surface of the puncture target site, such as skin. The use of the ultrasound-guided puncture assist device of the invention can increase the width of the target site tissue where a nerve block or vascular puncture is performed, and thus occurrence of mispuncture is preventable.