Background: The purpose of this study was to demonstrate the hypotensive efficacy and tolerability of latanoprost when used as monotherapy and as polytherapy associated with antiglaucomatous medication proven to be ineffective in keeping intraocular pressure under control. Methods: Three hundred and thirty-seven patients (672 eyes) affected by primary open-angle glaucoma and intraocular hypertension were recruited over a period of 10 years from the Glaucoma Centre, Department of Ophthalmological Sciences, University of Rome "Sapienza", and treated, subject to informed consent, with latanoprost 0.005% alone or in combination with other ocular hypotensive drugs. The patients were followed during this period at regular intervals, with determination of visual field, fundus oculi, visual acuity, and eventual onset of local and systemic side effects. Results: Latanoprost used as monotherapy and as polytherapy renders possible optimal and durable control of intraocular pressure in the form of one antiglaucomatous drug because it can substitute for one or more drugs and obtain the same hypotensive effect. Conclusion: Latanoprost can be described as the ideal hypotensive drug, not only because of its ideal compliance profile (only one daily dose in the evening), excellent hypotensive effect, and, above all, few systemic side effects. © 2012 Pacella et al, publisher and licensee Dove Medical Press Ltd.