Since their introduction in clinical practice beta-blocker drugs are known to be able to induce bronchospasm. However, this adverse effect may develop only in subjects with asthma, chronic bronchitis and/or airways hyper-reactivity. Although this potentially adverse effect of beta-blockers on the airways has long been recognized, its mechanism in inducing bronchospasm remains unclear. The Authors report a case of severe bronchoconstrictive episodes with respiratory failure following the administration of a timolol ophthalmic solution in a 51 yr old woman. Pharmacokinetics, preventive and therapeutic aspects of timolol eyedrop-induced bronchospasm are discussed.