This paper presents the results of peripheral iridectomy with scleral cautery performed on 42 eyes with various types of glaucoma. The technique described by Scheie1was employed throughout. The operation consists essentially of making a wide limbus-based flap, the application of thermal cautery to the area of sclera to be incised, a scratch incision over the root of the iris into the anterior chamber, reapplication of cautery to cause retraction of the wound edges, and a peripheral iridectomy. The flap, consisting of Tenon's capsule and conjunctiva, is closed with plain catgut. In most instances, the iris prolapses spontaneously and instrumental entry into the anterior chamber is unnecessary. When the iris did not prolapse spontaneously or with pressure on the posterior wound lip, the scleral incision was enlarged slightly with scissors to allow easy manipulation of an iris forceps. Of the 42 eyes operated on, 11 had acute primary narrow-angle glaucoma,