In a survey of 817 patients undergoing primary operations for retinal detachment, glaucoma was present in 9.5%. Ocular hypertension (intraocular pressure [IOP] greater than 21 mm Hg) was present in an additional 6.5%. Primary open-angle glaucoma; the type of glaucoma most frequently encountered, occurred in 4% of the patients. Aphakic eyes and eyes with peripheral anterior synechiae had high prevalences of glaucoma. A high percentage of eyes with posttraumatic angle recessions had either glaucoma or elevated IOPs. Miotics used in the treatment of glaucoma could not be definitely implicated as a cause of retinal detachment. The rate of successful retinal reattachment was the same, whether or not glaucoma was present. However, a good visual result occurred less frequently in patients with glaucoma.