Abstract Background Coronary artery spasm can occur either in response to drugs or toxins. This response may result in hyper-reactivity of vascular smooth muscles or may occur spontaneously as a result of disorders in the coronary vasomotor tone. Hyperthyroidism is associated with coronary artery spasm. Case summary A 49-year-old female patient with a 2-day history of intermittent chest pain and electrocardiographic evidence of myocardial ischaemia was referred for emergency coronary angiography. This revealed severe right coronary artery (RCA) and left main (LM) coronary artery ostial vasospasm, both subsequently relieved with administration of multiple doses intracoronary nitroglycerine. Intravascular optical coherence tomography showed absence of atherosclerosis and no evidence of thrombus or dissection confirming the diagnosis of coronary artery vasospasm. Laboratory tests of the thyroid function were performed immediately after coronary angiography revealing Graves’ disease as the cause of vasospasm. Discussion Our case represents a rare presentation of Graves’ disease-induced RCA and LM coronary artery ostial vasospasm. In patients with coronary artery vasospasm thyroid function study should be mandatory, especially in young female patients.