Argon laser trabeculoplasty (ALT) with 25 burn spots over the inferotemporal quadrant of the angle circumference was carried out in 71 eyes of 55 patients with open-angle glaucoma where maximum tolerable medication failed to control the intraocular pressure (IOP). Eighteen eyes underwent a second treatment, over the inferonasal quadrant. The overall success rate of the postoperative IOP control below 20 mmHg with continued medication was analyzed by means of a life-table method. It was 68 +/- 8% after 15 months. One-quadrant ALT gave approximately the same IOP control rate with less complications when compared to the results of the standard 180-degree ALT.