Acupuncture (from Lat. acus, "needle" (noun), and pungere, "prick" (verb) or in Standard Mandarin, zhn ju (), is one of the main branches of Traditional Chinese Medicine (others being herbal medicine and tui na). It is a therapeutic technique from that framework intended to restore health and well-being. The term acupuncture is often used by Westerners to refer to Chinese medicine generally. The technique involves the insertion of needles into "acupuncture points" on the body by trained practitioners. The needles most commonly used in present-day practice are made of stainless steel and are of approximately the same diameter as a medium thickness guitar string (from approximately .01" to .02"). Although the clinical efficacy of this practice is debated, the traditional theory underlying its mechanisms has no basis in modern scientific conceptions of physiology and is therefore considered by its critics to be a pseudoscience. While many of its practitioners and proponents promote it in a modern, clinical manner, acupuncture and related practices predate modern concepts of science.

In China, the practice of acupuncture can perhaps be traced as far back as the 1^st millennium BC, and archeological evidence has been identified with the period of the Han dynasty (from 202 BC to 220 AD). The practice spread centuries ago into many parts of Asia; in modern times it is a component of traditional Chinese medicine (TCM), and forms of it are also described in the literature of traditional Korean medicine where it is called chimsul. It is also important in Kampo, the traditional medicine system of Japan.