This study investigated the changes in the urinary hormone levels of female monkeys (Macaca fascicularis) after single-dose and long-term treatments with Pueraria mirifica (PM). The monkeys were separated into 3 groups (n=3) and orally treated with 10, 100, or 1,000 mg of PM in each group. Two series of experiments were performed. In the first series of experiments, the monkeys were orally treated with a single dose of PM. The experimental schedule was divided into a one menstrual cycle pretreatment period and a two menstrual cycle post-treatment period. In the second series of experiments, the monkeys were orally treated daily with PM for 90 days. The experiment schedule was divided into a one menstrual cycle pretreatment period, a three menstrual cycle treatment period, and a two menstrual cycle post-treatment period. Urinary samples were collected daily and assayed for the FSH, LH, estradiol, and progesterone levels. The results showed that there were no changes in the FSH, LH, estradiol, and progesterone levels after treatment with a single dose of 10, 100, or 1,000 mg of PM or after daily treatment with 10 mg of PM for 90 days compared with the levels observed during the pretreatment period. Daily treatment with 100 mg and 1,000 mg of PM for 90 days only produced a clear reduction in the urinary FSH levels. This suggests that changes of urinary FSH levels can be considered an indicator for study of estrogenic effects on hormonal levels in female monkeys.