Objectives: Polycystic ovary syndrome (PCOS) has the feature of excessive LH, hyperandrogenism and disturbance of folliculogenesis. Also, insulin, IGF-I and IGFBP-l are involved in the pathogenesis of PCOS. Various surgical and medical therapies have been used and the action mechanisms are related to the endocrine effect. Laparoscopic ovarian electrocautery or laser vaporization is effective in the restoration of ovulation and normal menstrual cycle with minimal invasive procedure especially in the patients resistant to medical therapy. Clomiphen citrate (CC) is used for the ovulation induction in pcas and the resistance is known to be related to insulin, IGF-I, IGFBP-l levels. This study was performed to evaluate the effect of the laparoscopic laser vaporization on the levels of LH, FSH, testosterone, IGF-I and IGFBP-l and on the ovarian response to clomiphen citrate in patients with CC-resistant PCOS. Materials and Methods: The fasting basal serum LH, FSH, testosterone, IGF-I and IGFBP-l level were measured in 10 PCOS patients with CC-resistance and 7 normal controls with regular menstrual cycle. In PCOS, after laparoscopic $CO_2$ laser vaporization, endocrine levels were measured in 1 week interval for 4 weeks and then compared with preoperative levels. Results: In PCOS group, mean serum LH/FSH ratio, testosterone, IGF-I levels were higher and IGFBP-l level was lower than control. LH/FSH ratio decreased from $2.51{pm}0.67$ to $1.7{pm}0.6$ (p<0.05) in 2 weeks, to $0.56{pm}0.2$ (p<0.01) in 3 weeks and to $1.41{pm}0.3$ (p<0.01) in 4 weeks after operation. Testosterone level decreased from $1.51{pm}0.82ng/ml$ to $0.65{pm}0.34ng/ml$ (p<0.05) in 2 weeks, to $0.56{pm}0.67ng/ml $(p<0.01) in 3 weeks after operation. IGF-I level also decreased from $436{pm}47.5{mu}g/l$ to $187{pm}38{mu}g/l$ (p<0.0l) in 1 week, to $167{pm}42{mu}g/l$ (p<0.01) in 2 weeks, $179{pm}55{mu}g/l$ (p<0.01) in 3 weeks and to $120{pm}43{mu}g/l$ (p<0.01) in 4 weeks after operation. IGFBP-l level showed no significant change. In 8 of 10 PCOS patients, ovulation was induced with low dose clomiphen citrate. Conclusion: Laparoscopic $CO_2$ laser vaporization restores normal menstrual cycle and ovulation through endocrine effect of decreasing LH/FSH ratio, testosterone and IGF-I level and increases the response to CC. Therefore it is useful for restoration of normal menstruation and induction of ovulation in CC resistant PCOS patients.