Coronary artery disease (CAD) is a leading cause of death and morbidity globally. Myocardial perfusion scintigraphy (MPS) is commonly used for the diagnosis of CAD, necessitating hyperaemia achieved either by physical exertion or by pharmacological stress, most commonly through use of a coronary arteriolar dilator. This is challenging in patients with respiratory conditions because exercise may be submaximal and adenosine is contraindicated because of the risk of bronchoconstriction. Regadenoson is the only selective adenosine A2A receptor agonist approved as a vasodilator in MPS. The risk of bronchospasm with regadenoson has been investigated in large, randomised trials; however, patients with the most severe respiratory conditions were not included. In this case series, we present the use of regadenoson MPS in five patients with moderate-to-severe lung conditions, including patients requiring lung volume reduction surgery and lung transplant. In all cases, regadenoson MPS provided valuable information for risk assessment and treatment optimisation. Although dyspnoea occurred in all patients, regadenoson was well tolerated without serious adverse events or bronchospasm; in no case was intervention required to treat dyspnoea.