This paper describes the use of a pulsed argon laser to perform iridotomies in 87 patients. Diagnosis include: primary angle closure glaucoma, narrow angle in the fellow eye of patients with primary angle glaucoma, pupillary block, and after incomplete surgical iridectomies. Laser iridotomy was achieved in 79% of patients. Blue eyes were slightly more difficult to penetrate. Success was almost 100% in those with pupillary block. Penetration was most difficult in patients with primary angle closure glaucoma (64%), but more easily accomplished in the fellow eyes of such cases (87%). In 13 patients surgical peripheral iridectomy was performed on one eye while the other eye was treated with laser iridotomy. No apparent significant long term differences were noted between the two eyes of the same individual. Complications of laser iridotomy include corneal burns, pupil distortion, synechia formation, lenticular opacities, iritis, marked pigment dispersion, sudden rise in intraocular pressure, and retinal burns. At this time a longer follow-up is required before it can be stated that a laser PI is more advantageous than a surgical PI. However, the laser's simplicity and ease of administration appear to warrant its continued use at this time.