A multicenter open-label study investigated the clinical effectiveness and economic feasibility of switching 142 patients from dual therapy to twice-daily monotherapy with brimonidine for glaucoma or ocular hypertension. Evaluations were performed at baseline and 2 (visit 2) and 8 (visit 3) weeks after the switch. Patients completed a questionnaire that rated medication-related visual function and satisfaction (comfort, convenience, vision, ease of remembering to use drops) at each visit. At visit 3, investigators, taking into account IOP measurements, safety, and responses on the questionnaire, recommended whether the patient should remain on brimonidine. A pharmacoeconomic analysis, including the number of visits, cost of medication, and success rates, compared the cost of dual therapy with that of switching to brimonidine monotherapy. Of the 131 patients who completed the study, 77 (59%) had no change or a decrease in IOP from baseline, and 53 (41%) had an increase. Investigators recommended that 77% of the study completers continue to take brimonidine monotherapy. Extending treatment with brimonidine for 12 months would achieve a significant cost savings of 16%. Brimonidine monotherapy is an efficacious and cost-effective alternative to dual therapy for glaucoma and ocular hypertension. Appropriate monotherapy may be as effective as dual therapy for many patients, and a clinically relevant trial such as this may be economically advantageous for testing a switch.