The di-zhen (DZ) is an ancient type of acupuncture needle with a history dating back more than 2000 years. Unlike modern acupuncture needles, the DZ is not inserted subcutaneously, and is safely and commonly used at the bedside. The mechanisms underlying its effects are not known. In this study, we measured sublingual and cutaneous body temperature, pulse rate, oxygen pressure (PO 2 ), oxygen saturation (SO 2 ) and carbon dioxide pressure (PCO 2 ) before and after DZ application in 25 healthy male volunteers. Serum levels of catecholamines (adrenaline, noradrenaline and dopamine) and white blood cells (WBCs; ratio and number) were traced for one week. Soon after DZ application, pulse rate, body temperature, PO 2 and SO 2 all decreased. The serum levels of adrenaline and noradrenaline increased, indicating sympathetic dominance, and the number of granulocytes was elevated. One week after DZ application, the number of lymphocyte increased. We therefore suggest that DZ affects body temperature, pulse rate, catecholamine secretion and immune function by inducing transient sympathetic dominance via actions on the autonomic nervous system. These effects are similar to the effects observed with modern needles, which are inserted subcutaneously. Therefore, we consider DZ treatment to be advantageous and safe in modern clinical practice, especially in postsurgical and terminal care, as it avoids the issues with infection and tissue damage sometimes seen with modern acupuncture needles.