Glaucoma is a pathological condition whose most important risk factor is increased intraocular pressure (IOP). The medical treatment of glaucoma essentially consists of compounds that are able to decrease the IOP. The compounds discussed in this review act in a different way, beta-blockers mainly inhibit the production of aqueous humor, whereas latanoprost decreases the resistance in the outflow channels. beta-Blockers are compounds with a well-known efficacy and safety profile and they are fairly inexpensive. Their systemic and local side effects are mainly cardiovascular and pulmonary adverse events, dry eye and keratopathy. Latanoprost, which has recently been introduced into the market, has been shown to be equally as effective, or better in lowering IOP in patients than timolol, although it is more expensive. Systemic reported side effects are anecdotal; local hyperaemia, keratopathy, hypertrichosis, increased pigmentation of eyelashes and iris, uveitis and cystoid macular oedema have been reported. A comparison of costs reveals that a 1-year therapy with timolol ophthalmic solution starts from 11.00 Euros and can reach 146.00 Euros for the most expensive preservative-free 1-day dispenser packages (approximately 13.5 times higher). For latanoprost once-daily administration, the cost for 1 years therapy is 98.55 Euros, approximately six times higher than generic or brand 0.5% timolol applied twice-daily. What are the factors influencing a change in therapy from beta-blockers to latanoprost? The only good reason is represented by a further deterioration in the visual field. This may occur, despite a significant reduction in IOP, because the reached IOP is not sufficient enough to avoid further deterioration because the patient's work or social activities do not allow a correct daily dosage of the compound (bad compliance); or as a result of treatment suspension, because of the development of systemic and/or local side effects. Changes in therapy must always be related to a failing control of the disease, as any therapeutic modification leading to an increase in the number of visits and additional examinations, consequently enhances the costs.