Plasma ACTH, cortisol, and cyclic-AMP levels of eleven heroin addicts were dertermined before and after treatment with a fast detoxification procedure using acupuncture and electrical stimulation (AES) together with the administration of limited doses of naloxone. At the end of the treatment period, the average plasma ACTH, cortisol, and cyclic-AMP level rose 130,83, and 24 percent, respectively. In view of the appearance of mild withdrawal signs during this method of treatment, the observed increases in ACTH and cortisol levels probably reflect the inability of AES to suppress withdrawal symptoms induced by naloxone completely. The mechanism underlying this new method of treatment is discussed in relation to AES's ability to stimulate the secretion of endorphins.