One hundred and twenty-eight eyes of 113 pre-surgical patients with open-angle glaucoma, treated with 360-degree orgon laser trabeculoplasty, were followed up for 24 months. Success was defined as an intraocular pressure below 23 mmHg as well as an intraocular pressure reduction of at least 20% with the same medical therapy as given before laser treatment, or less. The total success rate was 64%. In 79 eyes with capsular glaucoma the success rate was 76%, whereas in 49 eyes with simple glaucoma it was 45%. The success rate increased in groups with higher degrees of trabecular pigmentation, probably an effect of a higher proportion of eyes with capsular glaucoma in these groups. Baseline intraocular pressure had no influence on the success rate. No correlation was found between the amount of laser energy delivered and the degree of pressure reduction after 6 months. Neither was there any significant difference in laser energy levels between eyes showing successful results and those regarded as failures at the end of the 2-year follow-up period.