The authors evaluated the effectiveness and safety of bimatoprost using an open-label, non-comparative, three-month, community-based surveillance study. Patients (n = 458) with open-angle glaucoma or ocular hypertension received bimatoprost 0.03% ophthalmic solution as monotherapy, replacement therapy or adjunctive therapy. Bimatoprost produced a rapid, significant (p < 0.0001) reduction in intraocular pressure: monotherapy (34.6% reduction), replacement therapy (16.4% reduction); adjunctive therapy (24.1% reduction). Bimatoprost enabled more patients to achieve their pre-defined target intraocular pressure (p < 0.0001), compared to previous treatments, and significantly lowered intraocular pressure, regardless of the patients' baseline pressure level or history of pressure control. Bimatoprost was well-tolerated; the most commonly reported adverse event was conjunctival hyperaemia (19.9%). Most patients and ophthalmologists rated bimatoprost highly, compared to previously used treatments. The authors concluded that bimatoprost is an effective, well-tolerated treatment for lowering intraocular pressure in Thai patients with open-angle glaucoma or ocular hypertension.