Purpose: The Ocular Hypertension Treatment Study (OHTS) demonstrated that medical treatment of people with intraocular pressure (IOP) of ≥24 mm Hg reduces the risk of the development of primary open-angle glaucoma (POAG) by 60%. There is no consensus on which people with ocular hypertension would benefit from treatment. Design: Cost-utility analysis with the use of a Markov model. Methods: We modeled a hypothetic cohort of people with IOP of ≥24 mm Hg. Four treatment thresholds were considered: (1) Treat no one; (2) treat people with a ≥5% annual risk of the development of POAG; (3) treat people with a ≥2% annual risk of the development of POAG, and (4) treat everyone. The incremental cost-effectiveness ratio was evaluated. Results: The incremental cost-effectiveness ratios for treatment of people with ocular hypertension were $3670 per quality adjusted life-year (QALY) for the Treat ≥5% threshold and $42,430/QALY for the Treat ≥2% threshold. "Treat everyone" cost more and was less effective than other options. Assuming a cost-effectiveness threshold of $50,000 to 100,000/QALY, the Treat ≥2% threshold would result in the most net health benefit. The decision was sensitive to the incidence of POAG without treatment, treatment effectiveness, and the utility loss because of POAG. Conclusion: Although the treatment of individual patients is largely dependent on their attitude toward the risk of disease progression and blindness, the treatment of those patients with IOP of ≥24 mm Hg and a ≥2% annual risk of the development of glaucoma is likely to be cost-effective. Delay of treatment for all people with ocular hypertension until glaucoma-related symptoms are present appears to be unnecessarily conservative.