AIM: To investigate the effect of YAG laser peripheral iridectomy in difficult drug controlled acute angle-closure glaucoma. METHODS: Retrospectively analyzed 124 cases ( 124 eyes) of admission patients, among which males were 51 cases, females were 73 cases. Their admission diagnosis accorded with the clinical features of acute angle- closure glaucoma. After 24 hours'drug treatment, the intraocular pressure(IOP) of acute angle- closure glaucoma patients were still > 21mmHg, 51 eyes ( 41. 1% ) between 21 -35mmHg, 37 eyes(29. 8% ) between 36-50mmHg, 36 eyes (29. 1% ) >50mmHg. The range of visual acuity were light perception to 0. 3. All the cases accepted YAG laser peripheral iridectomy under topical anesthesia. The IOP, visual acuity, anterior chamber depth were observed postoperatively. After IOP was steady, trabeculectomy, glaucoma cataract combined with intraocular lens ( IOL) implantation, or single phacoemulsification combined with IOL implantation were performed respectively. RESULTS: Two days after YAG laser peripheral iridectomy, IOP was≤21mmHg in 28 eyes (22. 6% ), 22-35mmHg in 60 eyes (48. 4% ), 36 - 50 mmHg in 25 eyes(20.2% ), > 50mmHg in 11 eyes ( 8. 9% ). After laser surgery, visual acuity increased 3 lines in 33 eyes (26.6% ), 2 lines in 31 eyes (25. 0% ), 1 line in 44 eyes (35.5% ), no change in 16 eyes (12. 9% ), and the anterior chamber depth increased in 119 eyes ( 96. 0% ), postoperative hyphema in 98 eyes ( 79. 0% ). After IOP was steady, 37 eyes accepted trabeculectomy, 43 eyes accepted glaucoma cataract combined with IOL implantation, 44 eyes accepted phacoemulsification combined with IOL implantation. Followed up for 3 - 9 months, IOP ≤18mmHg were in 95 eyes, ≤25mmHg in 24 eyes, 26 - 35mmHg in 5 eyes, no hyphema, cystoid macular edema and other complications. CONCLUSION: YAG laser peripheral iridectomy can significantly reduce the IOP in difficult drug controlled acute angle - closure glaucoma, which provides safe and reliable condition for treatment of different glaucoma and is helpful to the protection and restoration of visual function, as well as increase the efficacy.