Objective To explore an optimal laser dose of transvaginal ultrasound–guided ovarian interstitial laser coagulation in management of anovulation in patients with polycystic ovary syndrome (PCOS). Design Randomized, controlled trial. Setting A reproductive medical center. Patient(s) Eighty women with PCOS and clomiphene citrate–resistant infertility underwent ultrasound-guided transvaginal ovarian interstitial yttrium aluminum garnet laser treatment. All subjects were divided randomly into four groups of A, B, C, and D. Intervention(s) Group A, one coagulation point per ovary; group B, two points; group C, three points; group D, four to five points. Main Outcome Measure(s) Postoperative ovulation rate, pregnancy rate, and some biochemical parameters. Result(s) The rates of ovulation in groups C (75.00%, 95% confidence interval [CI]: 51%–91%) and D (80.00%, 95% CI: 56%–94%) within 6 postoperative months were significantly higher than in groups A (5.00%, 95% CI: 0%–25%) and B (15.00%, 95% CI: 3%–38%). The pregnancy rates in groups C (45.00%, 95% CI: 23%–69%) and D (40.00%, 95% CI: 19%–64%) also were significantly higher than in groups A (5.00%, 95% CI: 0–25%) and B (10.00%, 95% CI: 1%–32%). The mean serum T levels were significantly lower in groups C (2.08 ± 0.62 nmol/L) and D (2.07 ± 0.42 nmol/L) compared with groups A (3.10 ± 0.63 nmol/L) and B (2.95 ± 0.63 nmol/L). Conclusion(s) One and two intraovarian laser coagulation points per ovary are associated with poor outcomes. Three points per ovary seem to represent the plateau of effective dose for the ovarian interstitial laser treatment in PCOS.