The effect of electro-acupuncture in the treatment of naloxone precipitated morphine withdrawal in mice was studied. Thirty minutes of acupuncture was enough to suppress withdrawal behaviors by more than 60%. Concomitant to the decrease of withdrawal behavior, there was a significant increase of brain beta-endorphin level in the acupunctured animals. Plasma beta-endorphin level of the treated and untreated group was not significantly different.