45 acne patients and 38 healthy subjects were assayed for serum testosterone and estradiol levels by RIA. The results showed that serum testosterone levels of male patients were normal, but serum estradiol levels were significantly higher (40%) than in healthy males. In female patients, estradiol levels were normal, but testosterone levels were significantly higher (47%) than in healthy females. Of the 18 female patients, 16 had various degrees of menstrual dysfunction, and some even had slight hirsutism. Therefore, male acne patients should not be treated with estrogen, and in female acne patients with ovarian dysfunction, artificial menstrual cycle therapy is recommended.