One hundred consecutive patients with intractable glaucoma underwent transscleral neodymium: YAG (Nd:YAG) cyclophotocoagulation using a standard protocol derived from a study of human autopsy eyes, and were followed prospectively for a minimum of 6 months. After the first treatment, 51 patients had a final intraocular pressure (IOP) between 7 and 20 mmHg (classified as "IOP success") and 17 more had an IOP less than 7 mmHg or more than 20 mmHg, but required no additional surgery ("qualified IOP success"). With one or more additional treatments, the totals rose to 65 IOP successes and 30 qualified IOP successes. Parameters associated with qualified success and failure were younger age and higher preoperative IOP. Forty-five patients in the cumulative IOP success and qualified IOP success groups had reduced visual acuity, although this could be attributed to other ocular problems in at least one half of the cases. Other postoperative complications included transient IOP rise in 23 patients, severe pain in 12 patients, and severe inflammation in 29 patients.