The feasibility of ultrasound-guided transvaginal interstitial laser treatment of the ovary (TILT) and its efficacy for ovulation induction was investigated in 3 hormone-therapy-resistant patients with chronic hyperandrogenic anovulation. TILT was performed at powers of 1-2 W and exposures of 75-600 s. Clear-cut hyperechogenic zones developed during laser irradiation with diameters of up to 13.7 mm. Spontaneous ovulation and/or hormonal changes after TILT did not occur. No adhesion formation was seen during a laparoscopy or laparotomy in 2 patients 6 months after TILT. In conclusion, TILT of the ovaries was simple to perform but so far the clinical results are disappointing. Further studies with a modified technique are necessary to further investigate the efficacy of TILT.