Over the past two decades, hemorrhages on the optic disc have become recognized as a common and significant sign of glaucomatous damage. It is not known what causes the hemorrhages, and since at least monthly examinations of the disc would be required to identify most hemorrhages, it is not clear whether some patients have them frequently while others do not, or whether hemorrhages occur in some phases of glaucoma more than in others. Because it is evident that disc hemorrhages precede glaucomatous change in the retinal nerve fiber bundle, the visual field, and the topography of the disc, "normal" patients with such hemorrhages should be considered glaucoma suspects or low tension glaucoma patients, depending on their intraocular pressures. The literature regarding the appearance, prevalence, location and recurrence rates of disc hemorrhages is reviewed, and their significance to the diagnosis of glaucoma is discussed.