Bedtime inhalation of a novel muscarinic M3 receptor antagonist markedly lowered ambulatory blood pressure (ABP), predominantly during sleep, in a chronic obstructive pulmonary disease (COPD) patient with masked nocturnal hypertension. This is the first case demonstrating that a bronchodilator significantly lowered ABP in a COPD patient with hypertension. This case suggests that bronchodilator therapy may have potential as a new antihypertensive strategy targeting the lung in hypertensive patients with impaired lung function. This "bronchoantihypertensive" therapy seems to be more effective for reducing sleep blood pressure in hypertensive patients with COPD and sleep hypoventilatory/hypoxemic syndromes.