Poor spermatogenesis in patients with inflammation of the genital tract is associated with scrotal hyperthermia. These patients can benefit from acupuncture treatment. We conducted a study to verify whether the influence of acupuncture treatment on sperm output in patients with low sperm density is associated with a decrease in scrotal temperature. The experimental group included 39 men who were referred for acupuncture owing to low sperm output. The control group, which comprised 18 normal fertile men, was used to define a threshold (30.5 degrees C) above which scrotal skin temperature was considered to be high. Accordingly, 34 of the 39 participants in the experimental group initially had high scrotal skin temperature; the other five had normal values. Scrotal skin temperature and sperm concentration were measured before and after acupuncture treatment. The five patients with initially normal scrotal temperatures were not affected by the acupuncture treatment. Following treatment, 17 of the 34 patients with hyperthermia, all of whom had genital tract inflammation, had normal scrotal skin temperature; in 15 of these 17 patients, sperm count was increased. In the remaining 17 men with scrotal hyperthermia, neither scrotal skin temperature nor sperm concentration was affected by the treatment. About 90% of the latter patients suffered from high gonadotropins or mixed etiological factors. Low sperm count in patients with inflammation of the genital tract seems to be associated with scrotal hyperthermia, and, consequently, acupuncture treatment is recommended for these men.