OBJECTIVES: To determine whether the body weight, body mass index (BMI), and basal serum level of LH, FSH, testosterone (T), dehydroepiandrosterone sulfate (DHEA-S) are related to the ovarian response to clomiphene citrate (CC) in patients with polycystic ovarian syndrome (PCOS). MATERIALS AND METHOD: From January 1996 to June 1997, total 57 patients with PCOS were enrolled in the present study. Women who had other infertility factors were excluded from our study. The ovulation induction using CC was used in all patients. The patients were grouped into 50 mg group, 100 mg group, and 150 mg group according to their daily CC dose. The patients were also grouped to ovulatory and non-ovulatory group. The body weight, BMI, arid basal serum level of LH, FSH, T, DHEA-S were measured in all patients on the 2nd or 3rd day of the menstrual cycle. Results were analysed with Student's t-test and Fisher's exact test. RESULTS: The body weight and BMI of the nonovulating group were significantly higher than those of the ovulating group in all groups (50, 100, 150 mg of CC). However, there were no significant differences of the level of LH and FSH between ovulating and nonovulating groups in all CC groups (50, 100, 150 mg). The level of T of nonovulating group was significantly higher in 50 and 100 mg of CC groups, but not in 150 mg group. The level of DHEA-S of the non-ovulating group is significantly higher in 50 mg group, but not in 100 and 150 mg groups. CONCLUSION: The body weight and BMI could be useful predictors of ovarian response to CC in patients with PCOS, and basal T and DHEA-S also might be useful in cases of low-dose CC treatment.